Almagro defied the odds to win the first two sets and found himself serving for the match in the third.
However, a combination of poor tennis from him and fantastic play from Ferrer saw the latter recover to win the final three sets and take the match 4-6 4-6 7-5 7-6 6-2.
Read below how the action unfolded.
2.07amHello all. Thanks for joining me for this second quarter-final of the day. This should be a belter between the Spaniards Ferrer and Almagro.
2.09amFerrer, seeded fourth, must surely be the best man in the Open era yet to reach a Slam final. His best performance here was the semi-finals in 2011.
2.10amAlmagro, seeded 10th, has never been past a quarter-final.
2.11amWarm-ups just about done, Ferrer will serve when we get underway.
2.12amI can't look beyond Ferrer here. I hope, however, that it at least goes to four sets.
2.13amFantastic start from Ferrer. Two aces begin this contest.
Ferrer 1-0* AlmagroHe then gets on top of a rally with Almagro going long and wins the opening game after a 26-shot rally. Very good start from Ferrer.
2.16amAlmagro starts well too, with Ferrer unable to return his first serve.
Ferrer *1-1 AlmagroThe 10th seed opens with a love game, he couldn't ask for any more than that. Both men comfortable in their opening service games.
2.20amWhat a backhand from Almagro. One-handed right across the court, superb.
Ferrer 2-1* AlmagroDespite that shot, Ferrer holds comfortably again, finishing off with a forehand that Almagro cannot return. No chance of a break for Almagro so far.
2.25amFerrer pulls back to 30-30 from 30-0, could he get a sniff of a break here?
Ferrer *2-2 AlmagroHe does at deuce, but after a good baseline rally Almagro earns the game point with a smash at the net after working Ferrer around the court.
Ferrer 3-2* AlmagroFerrer is just about on top of this as he holds to love. Absolutely perfect serving from him and Almagro will be wondering when his chance might come.
2.32amAlmagro managing to run Ferrer all over the court on some points, which really is not a common sight in tennis.
2.34amFerrer steers a marvellous return back past Almagro and suddenly it's 40-30 from 40-0.
Ferrer *3-3 AlmagroBut Almagro once more pulls off a sublime backhand right down the line. What a way to hold and it's still with serve half way through this set.
2.35amAlmagro turns defence into attack to take the first point of the next Ferrer service game.
2.37amIt's now 15-40 and the first break points go to Almagro.
Ferrer 3-4* AlmagroBREAK! Really expansive tennis from Almagro. He completely dominated the Ferrer serve in that game and deservedly breaks. This will be a big test of Ferrer now, can he respond straight away?
Ferrer *3-5 AlmagroAlmagro consolidates the break to 15 and is now just one game away form the opening set. He's been thoroughly impressive here and is well on top right now.
2.42amAbsolutely booming backhand from Almagro. That was hit so hard even Ferrer had no hope of returning it. Thumping shot.
Ferrer 4-5* AlmagroAfter that fantastic shot, Ferrer recovered really well and finished the game with his fifth ace. Almagro must serve for the set.
2.46amStrong start from Almagro, he's 30-0 up. This doesn't look like a man who has been beaten 12 times by his opponent.
2.47amAgain that backhand from Almagro! He had to reach low but it flew down the line for a superb winner and set point.
Ferrer *4-6 AlmagroSET! A double fault follows, but he did more than enough in that set to take it. Emphatic start from him, can he keep up that level in the second set?
Ferrer 4-6 1-0* AlmagroAlmagro brings it to 30-30 but Ferrer steps into a monstrous forehand before finishing it off with ace number seven. Good start from him, now can he get into his opponent's serve?
Ferrer 4-6 *1-1 AlmagroFerrer simple cannot respond if Almagro's serving is to stay hard and accurate. The 10th seed takes this one after a solid one-two with a forehand that Ferrer cannot get back over the net.
Ferrer 4-6 2-1* AlmagroExcellent stuff from Ferrer, who wraps up a service game to love that will surely give him a bit of a confidence boost. His ego has certainly taken a hit after that first set.
3.01amAlmagro still comfortable on serve. He's 40-15 up here.
Ferrer 4-6 *2-2 AlmagroAnother service hold and just the one break so far. Neither player has had a say in terms of breaks so far this set.
3.04amSuperb from Ferrer. He runs Almagro around the court before unleashing that backhand down the line for 15-15.
3.05amFerrer is giving himself a hard time here, screaming at himself on every error.
Ferrer 4-6 2-3* AlmagroBREAK! Almagro digs in on the Ferrer serve and converts only the second break point of the match. Both men were shouting at themselves in that game but Almagro gets the set and 3-2 lead.
3.13amFerrer is misplacing too many shots now. Twice he goes wide at the start of this one and it's 30-0.
Ferrer 4-6 *2-4 AlmagroAn ace and a well-worked forehand winner give Almagro an easy service game to consolidate his break. It's not looking good for Ferrer right now.
Ferrer 4-6 3-4* AlmagroFerrer responds well with a love game of his own, but he needs to start making inroads into the Almagro serve.
3.18amHere is perhaps his chance. He's up 0-30. Big test of Almagro's serve.
3.20amAlmagro saves both, the second with a huge serve down the middle.
3.21amOnce more there's that backhand down the line! Four times he's hit winners from deep that Ferrer hasn't got close to.
Ferrer 4-6 *3-5 AlmagroFrom 15-40 down Almagro holds. Ferrer's chance to level the sets has gone, and it was once more down to brilliant hitting from his opponent. Ferrer to serve to stay in it.
3.23amBREAKING! The order of play for the second set of quarter-finals tomorrow has been announced. Take a look here.
3.24amFerrer does seem to be turning the screw, certainly on his serve. He's 40-0 up but desperately needs to break.
Ferrer 4-6 4-5* AlmagroAlmagro gets a couple back with another good backhand but Ferrer holds to make Almagro serve out the set, if he can.
Ferrer 4-6 *4-6 AlmagroSET! Just as he did last set, Almagro serves out easily and he's now two up. If Ferrer is going to win this he'll need to take it in five. He'll also need to improve!
3.29amThis seems like a good place to take a break. Michael Penkman is on hand to describe the next half an hour. A huge 30 minutes in Ferrer's tournament.
3.31amThanks Matt. Yes indeed, it is a crucial 30 minutes in which I join you. If he can get an early break then who knows what could happen.
Ferrer 4-6 4-6 1-0* AlmagroFerrer quickly gets to 30-0, before ripping an inside out forehand winner to go within a point of holding. He finishes with an ace to go ahead. Can he do anything on Almagro's serve now?
3.37amAlmagro goes long with a backhand, which has been working well for him so far. That gets Ferrer to 15-30, but some brutal hitting from Almagro sees him square up at 30-30. Ferrer was scrambling and gave his opponent an easy chance to smash a volley at the net.
3.38amFerrer attacks Almagro's serve with a brilliant forehand down the line before coming into the net. Almagro can't find the pass. That brings up break point but Ferrer rifles the ball into the net. Deuce.
Ferrer 4-6 4-6 *1-1 AlmagroThe fifth seed continues to make the errors. Almagro blasts another ace to hold after Ferrer found the net at deuce.
Ferrer 4-6 4-6 2-1* AlmagroFerrer once again claims the first two points on his serve, before Almagro rushes the net. Ferrer puts too much into the cross-court pass, but a couple of errors from Almagro sees him hold.
3.46amFerrer is missing quite a bit. He had Almagro on the move from side to side there, but dragged a forehand into the tramlines.
Ferrer 4-6 4-6 *2-2 AlmagroAlmagro holds, but it's Ferrer who continues to baffle with uncharacteristically poor play. His opponent isn't really having to work very hard for this, although that may seem unfair to Almagro, who has played very well.
Ferrer 4-6 4-6 3-2* AlmagroIt's a comfortable hold for Ferrer. He really needs to step up to the Almagro serve here, because he's not even testing it at the moment.
3.52amStrange request from Almagro. He's asking the umpire where he lost his challenge in this set. "It was on the centre service line," the umpire reminds him, after checking with someone on his hand radio.
Ferrer 4-6 4-6 *3-3 AlmagroNever seen Ferrer surrender so meekly. He's still on serve in this set, but took just one point off Almagro in that last game. He just doesn't look himself today.
3.55amFerrer goes for a drop shot, but finds only the net. The shot wasn't really on and Almagro was going to close it down. He's run out of idea, the fifth seed. He screams into his towel in frustration as Almagro is 0-30 up.
Ferrer 4-6 4-6 3-4* AlmagroBREAK! Now the racquet is slammed into the plexicushion with Almagro three break points to the good. Ferrer then goes long to confirm a break to love. Almagro sailing through now.
3.58amRight, I'm handing back over to Matt now as victory looks all but certain for Almagro. Bye for now folks.
3.59amThanks, Michael. We're at 15-15 in Federer's response to break straight back. Which he has to do, really.
4.01amFerrer gets himself into a rally but again uncharacteristically misses with a backhand for 40-30 Almagro.
Ferrer 4-6 4-6 *3-5 AlmagroThe 10th seed finishes with an ace, and is now one game away from a first win over Ferrer and a first semi-final appearance.
Ferrer 4-6 4-6 4-5* AlmagroWhat a forehand from Ferrer to go up 40-0 in this game and an ace sees him take a love game and put the pressure on Almagro to see it out. He's taken 40-0 in both the previous sets, but this is a different ask entirely.
4.05amPossibly the biggest service game of his career to date this for Almagro... he starts fantastically well with a few big forehands.
4.06amFerrer goes up 15-30 with some excellent movement and footwork. A slight look-in here.
4.08amOh what a forehand! He works this point all over the court and steps into a thunderous forehand right down the line. Two huge break points.
4.09amBefore bold net play allows Almagro to finish with the volley with the whole court to aim at. Deuce.
4.10amAnother break point after Almagro starts to tighten up.
Ferrer 4-6 4-6 *5-5 AlmagroBREAK! Oh it's game on now! That was a game with top five player in the world written all over it. He's back on serve and picks up his first break at the very last time of asking!
4.13amOh he's turning it on now! An unbelievable backhand on the run goes flashing past Almagro on his near side.
Ferrer 4-6 4-6 6-5* AlmagroNow Almagro must serve to save the net. Quite a turnaround these last few minutes and we've started to see the best of Ferrer. There's just a sense here... can he take it all the way? You bet he can, but there's a mountain to climb first, starting with a break here or a tie break win.
4.17amThe spring is back in his step now as Ferrer gets it to 0-30.
Ferrer 4-6 4-6 *7-5 AlmagroSET! He looked down and out but Ferrer breaks again after Almagro goes long. Four games straight for Ferrer and you just feel this is going to five. You have to feel for Almagro who was a couple of points away form victory, but he can only bame himself really.
4.21amHow can Almagro respond here? He has to be deflated and now Ferrer is using his entire repertoire - a sublime drop shot on display just then.
Ferrer 4-6 4-6 7-5 1-0* AlmagroAnd the fourth seed takes another love game. That's nine straight points as well, Almagro has to go back to the tennis he played for almost three sets.
4.24amNow Ferrer is up 15-30 on the Almagro serve. The 27-year-old is missing all the shots he was making in the previous couple of hours. However, he responds with a lovely subtle pass.
Ferrer 4-6 4-6 7-5 *1-1 AlmagroA good hold from Almagro from behind. It was vital that he regained his composure and he did with a few big serves that got him out of trouble.
4.27amHe misses a simple return forehand to let Ferrer back in but he now has two big break points.
Ferrer 4-6 4-6 7-5 1-2* AlmagroBREAK! Fantastic conversion rate from Almagro on break points. He has four from four! Ferrer had regained his form but has let Almagro back in. He's furious with himself! Can Almagro hang on in this set after throwing away the last one?
4.33amUneblievable point at 0-40. Ferrer defends three straight smashes before finally Almagro wrong-foots him for the winner.
Ferrer 4-6 4-6 7-5 3-2* AlmagroIt's a Jekyll and Hyde performance from Almagro. Since the chance to serve for the set Almagro has thrown so many points away. Ferrer is playing far better but Almagro is beating himself as well.
4.37amNow would be a good time for a Ferrer break, so Almagro must hold. He's started well and is 30-0 up.
4.38amA double fault and sublime forehand accuracy from Ferrer levels it at 30-30.
Ferrer 4-6 4-6 7-5 *3-3 AlmagroHe just about holds after severe Ferrer pressure. Almagro's service games are getting longer while Ferrer's are flying by at the moment.
4.41amBetter from Almagro. He attacks the serve and finishes off with a good forehand down the line.
4.42amBrilliant! Both men play some big shots in a rally but that backhand returns for Almagro and he's 0-30 up. Can he take advantage?
4.43amAgain the backhand gets the point and he's got two break points.
Ferrer 4-6 4-6 7-5 3-4* AlmagroBREAK! Four from four in breaks becomes five from five. Incredible conversion rate from Almagro and he earned that one with a couple of huge backhands. Pressure right back on Ferrer.
4.45amGreat start from Almagro. Two aces to go 30-0 ahead.
4.47amFerrer fights his way back into it with some deep, corner forehands and it's 30-30.
4.48amHow did he win that point Ferrer? Almagro throws down a huge ace and follow-up forehand but Federer defends before winning with a forehand of his own. Break point.
Ferrer 4-6 4-6 7-5 *4-4 AlmagroBREAK! He's done it again! This time it's taken the very, very best of Ferrer. The winner is a splendid soft-handed volley from a powerful Almagro passing attempt. Back with serve.
4.51amThat Ferrer forehand is on fire now. He crafts a superb point, that is finished with Almagro hitting the net for 30-15.
4.52amBackhand down the line from Almagro, and that's the best of his five or six today. Incredible to bring it to deuce.
4.53amBreak point.. Remember he's five from five..
Ferrer 4-6 4-6 7-5 4-5* AlmagroBREAK! The remarkable 100% break point conversion continues! Almagro breaks again and he again serves for the match. Three breaks running in this match and Ferrer needs a fourth to save the match.
4.56amFirst point to Ferrer, with some more forehands right into the corners.
4.57amNow two break points Ferrer.. is Almagro about to choke again?
4.59amAlmagro saves the second with an unbelievable forehand from deep in the shadows!
Ferrer 4-6 4-6 7-5 *5-5 AlmagroBREAK! What a huge break for Ferrer! Both men played some great tennis in that game, but Almagro makes the crucial error and he's thrown it away again!
5.05amAlmagro finds himself up 15-30 here. Surely we won't see break number five running?
5.05amWe may well - its not 15-40. With his 100% conversion rate, it looks good.
5.06amThey've both gone! The second one he's on top of the point but puts a backhand long. Poor.
Ferrer 4-6 4-6 7-5 5-6* AlmagroBREAK! Ferrer saves a series of break points but they keep coming and eventually Almagro takes one. Third time lucky serving for the match? Ferrer is fuming at himself, a rare display of emotion today.
5.12amMaybe the new balls will do him good. Good start, volleying for 15-0.
5.13amFerrer is now up 15-30. Almagro battles on Ferrer's serve but seems to lose fight on his own. Now 15-40!
Ferrer 4-6 4-6 7-5 7-6 *5-2 AlmagroBREAK! Ferrer is cruising now as much as Almagro is limping. He breaks with a perfect lob, and I mean inch perfect, to move to withing one game. He will serve for the match.
Ferrer 4-6 4-6 7-5 7-6 6-2 AlmagroGAME, SET AND MATCH! No problems for Ferrer seeing out the match. He shows Almagro how it is done and the younger of the two will be ruing a huge missed chance to reach his first Slam semi-final.
5.58amThat's it from me on this one. I'll be on Makarova vs. Sharapova shortly. See you over there.