That form was reflective in a three-set victory over the Argentine, during which Ferrer overcame his opponent's powerful ground strokes and his own recent schedule to claim an 11th straight win.
Below is our minute-by-minute tale of how the match unfolded.
7.38pmAs I have already mentioned, Ferrer and Del Potro are the last of the eight participants to begin their tournaments. The mathematicians amongst us will have figured out that means three matches have already taken place. Here are the results from the 02 thus far...
7.40pmEarlier today, title-holder Roger Federer began his defence with a convincing straight-sets win over Janko Tipsarevic.
7.43pmWorld number one Novak Djokovic was also victorious in his opening rubber, producing a battling performance to negotiate a potentially tricky opponent in the shape of Jo-Wilfried Tsonga.
7.46pmAndy Murray's come-from-behind win over Tomas Berdych gave the home support reason for cheer when the tournament began on Monday afternoon.
7.50pmBut it is not just a singles competition being hosted in London this week, oh no. We have doubles as well - and a result just in from the 02 Arena: Radek Stepanek and Leander Paes 6-4 7-5 Aisam-Ul-Haq Qureshi and Jean-Julien Rojer.
7.52pmThe completion of that match means that Ferrer vs. Del Potro is nearing its start. Let's preview this match then, should be a good one!
7.54pmSkybet have Del Potro a 8/13 favourite to beat Ferrer, who you can get at odds of 5/4 with the same bookmakers.
7.55pmThose odds aren't reflective of recent form, but could be explained by Ferrer's hectic recent schedule.
7.56pmFerrer's winning campaign in Paris last week means that he has only had two days rest ahead of this clash. Del Potro should enter the fresher, that's for sure.
7.59pmHowever, I wouldn't read too much into that. Ferrer is renowned for his almost endless endurance. The 30-year-old also has an excellent head-to-head record against his opponent tonight...
8.01pmHe has won five out of seven matches against the Argentine, although both of Del Potro's victories have come on tonight's hard-court surface.
8.02pmThe players are out and straight into the coin toss. Del Potro wins and surprisingly chooses to receive first against the left-hander.
8.05pmDel Potro is returning to the season-ending tournament for the first time since 2009, where he was a beaten finalist. He also won the US Open in the same year, but has since struggled with a succession of injuries.
8.07pmHe has managed to stay out of the treatment room this year though and find consistent enough form to climb back into the world's top 10. The players are warming up now.
8.08pmTime is called be the umpire. The start is imminent, which means prediction time! Hmm, difficult one to call...
8.10pmI will plump, against the bookmakers, for David Ferrer. We will see how big a factor fatigue will play, but I am expecting the Spaniard to be on a high following his maiden Masters title win in Paris.
8.11pmFERRER 1-0 DEL POTRO Here we go then, Ferrer serves and I have something to get my teeth into straight away as Del Potro challenges on the first point. It is unsuccessful though, and Ferrer draws first blood by holding the opening game fairly comfortably.
8.13pmSo, a wasted challenge from Del Potro there. Remember, each player has three challenges per set, and an extra one should the set go to a tiebreak.
8.15pmFERRER 1-1 DEL POTRO A couple of mishits from Ferrer lead to unforced errors and Del Petro joins the Spaniard in holding his first service game without concern.
8.19pmBreak point opportunity wasted from Del Potro as he sends a second-serve return long. Ferrer had nearly gifted him the game with a pair of forehand errors of his own. Deuce.
8.21pmFERRER 2-1 DEL POTRO Ferrer produces a lovely backhand down-the-line winner before producing a stiff wrist at the net to drop a difficult volley just inside the line.
8.25pmBREAK! FERRER 3-1 DEL POTRO Ferrer is clinical where Del Potro wasn't by claiming an early break in this first set. Superb play from the world number five, who ends a long exchange of baseline shots with a precise forehand winner. Del Potro approaches the net on break point and sends a volley wide to give Ferrer the advantage.
8.27pmFERRER 4-1 DEL POTRO Quick service game from Ferrer, who holds to love thanks in part to a pair of aces. If the Spaniard is serving well, that is a sign that he is really at the top of his game.
8.46pmFERRER 5-3 DEL POTRO Despite a second poor challenge call, Del Potro holds to stay in this opening set...for now. Ferrer now has the chance to serve for a one-set lead.
8.31pmFerrer is sniffing consecutive breaks here. He races into a 30-love lead, with the help of a Del Potro double fault, and is inches away from moving onto break point when his forehand passing shot on the stretch drops just the wrong side of the line.
8.34pmFrom 30-30, Ferrer gets the aid of a fortunate bounce of the net to set up break point, but is moved around the court well by Del Potro, who hits a simple overhead to take us to deuce.
8.36pmAwesome stuff from both players as Del Potro moves Ferrer from side to side and watches on in shock as the Spaniard somehow reaches each to return. Del Potro eventually tires Ferrer into submission, as he lets a forehand from the Argentine past him on the baseline.
8.38pmFERRER 4-2 DEL POTRO Important hold for Del Potro, who survives the closest of Ferrer challenges to prevent surrendering his serve for a second time. A further break there could have been curtains for the former US Open champion in terms of this first set.
8.41pmFERRER 5-2 DEL POTRO A lack of patience from Del Potro at the baseline as two unnecessarily attacking forehands produce two unforced errors and allow Ferrer a comfortable hold.
8.44pmDel Potro waves an apologetic hand at Ferrer after he gets the benefit of a lucky net bounce to claim his first forehand winner of the match. We've had to wait eight games for that, which is so unlike the big-hitting Argentine.
8.50pmSET! FERRER 6-3 DEL POTRO And he takes it! Superb opening set from Ferrer, who looks every inch the player that has won in Valencia and Paris in recent weeks. He dropped six points on serve during that set, and there is no sign of the supposedly wary figure many thought would suffer from his congested fortnight.
8.55pmFERRER 6-3 0-1 DEL POTRO Good response from Del Potro, whose first serves seemed to have greater fizz than they did throughout the first set. He forces Ferrer into uncomfortable returns and from then on is able to dictate the point and claim a hold to 15.
8.59pmDel Potro finally gets a challenge right to keep Ferrer at 40-30 and force the left-hander to serve out for the game once more.
9.01pmFERRER 6-3 1-1 DEL POTRO Which he does after an epic rally! Del Potro gives Ferrer everything he has on the forehand side but the in-form Spaniard shows great determination to stay in the point and then pinch it with a delightful passing shot.
9.04pmExcellent from Ferrer, who forces Del Potro to deuce with a well-executed inside-out forehand.
9.06pmGreat response from Del Potro to take the advantage with a superb cross-court forehand. He follows that up with a double fault though, which is rather typical of his evening thus far.
9.08pmHow ironic. The one time Del Potro decides not to challenge, the backhand from Ferrer was comfortably out. The Argentine saves break point though with a ferocious ace out wide.
9.10pmThe two players exchange forehand winners and Del Potro then saves his second break point of the game with another powerful serve that Ferrer cannot force back over the net.
9.12pmThis now 12-minute game is turning out to be the hardest fought of the match thus far as Del Potro produces a brilliant forehand winner down the line to save break point again, after he had gifted Ferrer that opportunity with another double fault.
9.14pmFERRER 6-3 1-2 DEL POTRO Big hold from Del Potro. If he would have lost that fiercely contested game you feel he might have started to get the impression it just wasn't his night.
9.18pmRare error from Ferrer, who attacks the net but drops a simple volley over the baseline. He calls for a blush-saving challenge, but no luck. Face it David, you missed one - it happens to the best!
9.20pmA powerful winner from Del Potro forces deuce, and Ferrer gains initially gains the upper hand before hitting wide to take us back to square one.
9.22pmBREAK! FERRER 6-3 1-3 DEL POTRO Del Potro breaks the Ferrer serve for the first time tonight, much to the joy of the crowd who may have been fearing a short match when Ferrer was well on top during the first.
9.24pmFERRER 6-3 1-4 DEL POTRO All change now as the momentum swings Del Potro's way further courtesy of an emphatic hold to love from the Argentine.
9.28pmFERRER 6-3 2-4 DEL POTRO Ferrer shows that he won't be put off by Del Potro's resurgence, producing a love service game of his own to reduce the deficit to two games.
9.33pmFERRER 6-3 2-5 DEL POTRO Del Potro makes another important hold to move to within one game of levelling this match at a set apiece.
9.36pmFERRER 6-3 3-5 DEL POTRO Ferrer will force Del Potro to serve for parity though after surrendering just a point on his way to holding.
9.39pmBig serves at a big time from Del Potro, who fires a powerful one down the middle that Ferrer can only return long, before following up with an ace out wide. Set point.
9.40pmSet point wasted! Ferrer shows great technique to get over the bouncing ball and hit a great backhand return deep, which Del Potro can only knock long in response.
9.44pmSET! FERRER 6-3 DEL POTRO 3-6 Del Potro closes out the second set in style with a deft drop shot, the first one I've witnessed tonight. This one is going to a decider! Will fatigue play a factor for Ferrer?
9.49pmFERRER 6-3 3-6 1-0 DEL POTRO Ferrer gets us underway in this third set and steals a long rally with a marvelous passing shot. He then produces two big serves which allow him to control the remaining points and hold the opening game of this decider.
9.52pmBrilliant from Ferrer, who produces a forehand return winner to complete a three-point salvo that has earned him as many break points.
9.54pmBREAK! FERRER 6-3 3-6 2-0 DEL POTRO After Del Potro sends down two massive serves to bring the score back to 30-40, the Spaniard hits a sensational cross-court passing shot to claim an early break in this crucial set.
9.56pmFERRER 6-3 3-6 3-0 DEL POTRO The 02 Arena applaud more great tennis from Ferrer, who holds to fifteen to take firm control of this match.
10.00pmFERRER 6-3 3-6 3-1 DEL POTRO Del Potro gets off the mark in the third set, but his forehands that had so much fizz behind them in the second seem to be less powerful now.
10.03pmFERRER 6-3 3-6 4-1 DEL POTRO Promising signs from the Argentine, who takes two points from the Ferrer serve and nearly forces deuce with a backhand down-the-line that clips the top of the net. It may not be a break, but it is pressure on the Ferrer serve at least.
10.06pmThe top of the net denies Del Potro again, with Ferrer seemingly beaten from another delicate drop shot from the world number seven.
10.09pmFERRER 6-3 3-6 4-2 DEL POTRO A seventh ace of the match wraps up another hold for Del Potro but it is on Ferrer's serve where this match will be decided now. Del Potro needs a break, and he'll likely only have two opportunities to get it...
10.12pmDel Potro fights back from 30-love down to level scores with some determined play before Ferrer returns a blistering forehand into the net to give Del Potro a hard-fought break point.
10.15pmBREAK! FERRER 6-3 3-6 4-3 DEL POTRO A succession of massive forehand drives wear down Ferrer and we are back on serve in this deciding set! Del Potro will serve now, with new balls.
10.17pmPlenty of Del Potro's success on serve has come from sending them out wide and he races into a 30-love lead thanks to a pair that Ferrer cannot return.
10.19pmFERRER 6-3 3-6 4-4 DEL POTRO Three straight games now for Del Potro and the momentum has again swung in his favour. Ferrer will have to show those battling qualities he is famous for to halt this comeback.
10.21pmFERRER 6-3 3-6 5-4 DEL POTRO And he does demonstrate those qualities, as well as some guile and assurance on his way to holding to love. Del Potro serving to stay alive in this group-stage match.
10.24pmAdvantage Ferrer here as the Spaniard lures Del Potro off the baseline and the resulting poor shot eventually sets up the world number five for a simple overhead winner. 0-30.
10.28pmGAME, SET, MATCH! FERRER 6-3 3-6 6-4 DEL POTRO Del Potro hits a forehand long to give Ferrer victory, which is his 11th on the bounce. A superb display of strokeplay and immense physical conditioning from the Spaniard, who defied his supposed fatigue to knock off a Del Potro in three sets.
10.30pmFerrer's superb season goes on and on. He has won more matches and ATP tournaments than anybody else this year, and he looks to be in the sort of form which could see him cap off a career-best campaign with another title in London.
10.32pmDel Potro played some of his best tennis at times during this encounter, but just couldn't find enough consistency, especially on serve. The beauty of such a round robin tournament means that the Argentine has a second chance though. He has Janko Tipsarevic next up on Thursday.
10.35pmFerrer returns to action on the same day, where he faces long-time 'bogey' opponent Roger Federer. Then again, Federer is many people's 'bogey' opponent. Ferrer's record against the 17-time Grand Slam champion is 13 losses and zero wins, but he is in the form of his life, so who knows?
10.37pmBefore that though, Sports Mole will be bringing you live coverage of tomorrow's Group A matches. Tomas Berdych plays Jo-Wilfried Tsonga in the evening, but the action begins with the salivating prospect of Novak Djokovic vs. Andy Murray. They have had so many great matches this year, and I'm betting on another Wednesday afternoon.
10.40pmUntil then though, it is goodbye from me. Thanks for joining Sports Mole this evening. You can read a match report on tonight's clash here.