It looked as though Daryl Murphy's second-minute header against his former club would be enough to separate the two teams until an action-packed period of stoppage saw three more goals fly in.
Salomon Rondon initially appeared to have forced penalties with an equaliser in the 92nd minute, but Matty Cash hit straight back to restore Forest's lead before Gil Dias capped off the scoring moments after Newcastle had been denied a penalty at the other end.
Find out how all of the action unfolded courtesy of Sports Mole's minute-by-minute updates below.
The second round got off to a typically action-packed start last night with goals galore and a few shocks too boot, and Forest will be looking to pull off another here at the expense of Rafael Benitez's Newcastle.
It is a clash between an unbeaten side and a winless side in terms of the 2018-19 campaign so far, but that only tells half of the story.
I will tell the rest of it in a short while, but first let's check out the team news...
The much-debated system has been disposed of, as expected, by Benitez for tonight's match as he switches back to his usual formation - albeit with a number of personnel changes, as is customary in this competition now.
Benitez makes seven from the weekend defeat to Chelsea, with Schar, Fernandez, Clark and Ki the only players to keep their places in the side.
The loanee winger was ineligible to face his parent club at the weekend, which means that tonight is his first change to banish the memories of his horror show against Cardiff the week before.
Kenedy failed to complete a single pass in the first half in South Wales, should have been sent off in that opening 45 minutes and then missed a 96th-minute penalty which would have won his side the match. It was a performance labelled by many as one of the worst individual displays in Premier League history.
Lascelles was reportedly involved in a training-ground bust-up with Matt Ritchie in the wake of the defeat to Chelsea, though, so the skipper has certainly been in the news for the wrong reasons lately. Forest are his former club, but he has not recovered from an ankle problem in time to feature tonight.
The likes of Darlow, Sterry, Atsu and Longstaff also come into the starting lineup, with Dubravka, Yedlin, Dummett, Ritchie, Diame, Murphy and Rondon all dropping out.
Jack Colback is another potentially-key player who misses out for the home side this evening as he is currently on loan from Newcastle and is ineligible to play against his parent club.
Costel Pantilimon is replaced in goal by Steele, while the likes of Hefele, Bridcutt and Carvalho also come into the side alongside Lolley. Not wholesale changes, but enough to keep the team fresh.
There are four players to have featured from the start in that shootout victory over Bury, the weekend draw with Birmingham and again tonight, and those are Byram, Robinson, Watson and Murphy.
Murphy averaged a goal every three games during that time - six in 18 appearances - but coming into this match he has two goals in his last three appearances.
Home advantage can, of course, be a major thing in these cup competitions, and in addition to that there is also the headline of Forest coming into the game unbeaten so far this season, whereas Newcastle are winless in the 2018-19 campaign.
Forest may be one of only five Championship teams yet to taste defeat, but four of their five league outings so far have ended in draws and that leaves them in the bottom half of the table - behind plenty of teams who have lost this term.
The most recent of those was a dramatic affair against Birmingham on Saturday, when Forest needed two goals in the final 15 minutes to rescue a point. Lolley and Murphy provided them - the latter in the 87th minute - to overcome their two-goal deficit.
It was by no means straightforward; Bury took the lead after only two minutes and held that advantage away from home for longer than 90 minutes until Matty Cash equalised three minutes into injury time. The game went straight to penalties, but that was by no means the end of the drama as it took 22 spot kicks to separate them, with Forest finally running out 10-9 winners.
It is a run which stretches back to April 10, while their defeat to Brentford on that date is their only home loss in their last 11 such outings - a significant improvement on their run prior to that.
Forest have only won two of their last 11 EFL Cup home games inside normal time, with five of those either going to extra time - which is no longer an options due to rule changes this year - or penalties. Their last two have ended in victory, though, including that shootout win over Burnley in the first round.
However, their overall record in this competition is comparable to some of the Premier League's very best, having lifted the trophy four times before. Only Liverpool, Manchester United, Aston Villa, Chelsea and Manchester City have ever won the trophy more, although Forest's last triumph came in 1989-90.
Since Newcastle last picked up a major trophy - the FA Cup in 1955 - Forest have won the top-flight title and two European Cups, not to mention a few other trophies. It really is a surprisingly long wait for a team with such a big fanbase which has been in the top flight for the vast majority of that time.
Tonight marks the beginning of their latest hope that they can go one better this time around, although a year ago their journey was ended at the first hurdle by the very team they find themselves up against tonight.
Indeed, the last time that occured, they had failed to make it that far in seven successive campaigns from 1977-78 to 1983-84.
Tottenham Hotspur and Chelsea were the opponents in their opening two home games of the campaign, and they fought admirably in both only to succumb to 2-1 defeats on each occasion. Lady Luck seemed to abandon them too, with Spurs awarded a goal by goalline technology when the ball had crossed the line by a matter of millimetres, while against Chelsea they lost to a very soft penalty and an unfortunate own goal.
Benitez offered no apologies despite seeing his side have only 19% possession and complete a whopping 700 passes fewer than their opponents, and but for some bad luck his controversial approach to the game could well have paid off.
Things get no easier for the Magpies either; they face Manchester City at the Etihad this weekend before taking on Arsenal in their first game back after the international break.
The Magpies have struggled for goal in the latter stages of that run too, netting just once in their last four away outings across all competitions.
EFL Cup games are always difficult to call and this is likely to be a tight contest considering Forest's record of draws so far this season. Newcastle's winless run is not as bad as it looks on first glance, though, so we're backing the visitors to progress.
SPORTS MOLE SAYS: Nottingham Forest 1-2 Newcastle
Mitrovic gave Newcastle an early lead on that occasion before the 90 minutes eventually ended at 2-2. Forest then got the extra-time winner to secure their place in the third round.
These two sides have met on 110 previous occasions, with Newcastle winning 49, drawing 27 and losing 34 of those.
The last EFL Cup clash here saw Newcastle emerge victorious in entertaining fashion, meanwhile, with Fabricio Coloccini scoring a 120th-minute winner to seal a 4-3 victory.
NOTTINGHAM FOREST STARTING XI: Steele; Byram, Hefele, Fox, Robinson; Bridcutt, Watson, Lolley, Carvalho, Dias; Murphy
NEWCASTLE STARTING XI: Darlow; Sterry, Schar, Fernandez, Clark; Atsu, Ki, Longstaff, Kenedy; Muto, Joselu
Daryl Murphy scores against his former club with a smart glancing header from close range, although the plaudits must go to Byram. He skips past Kenedy far too easily down the right flank before whipping in a beauty of a cross which is begging to be converted by the in-form striker.
⚽️ Daryl Murphy scores his 1st ever League Cup goal, in his 16th app in the competition. It is also his 100th goal in senior British club football 💯 pic.twitter.com/IRY2QBR1Sr— Sky Sports Statto (@SkySportsStatto) August 29, 2018
2 - Daryl Murphy is just the second player to score both for and against Newcastle United during Rafael Benitez's reign, along with Jacob Murphy. Law. pic.twitter.com/pa2s0dIUlv— OptaJoe (@OptaJoe) August 29, 2018
Forest have played some really slick football so far and started the match really well, but Newcastle grew into the first half and saw more of the ball as the 45 minutes progressed. Clear chances have been few and far between for the visitors, though.
Byram was the architect of the goal, skipping past Kenedy far too easily down the right flank before delivering a perfect ball into the middle which Murphy glanced past Darlow from close range.
Both Muto and Fernandez almost got on the end of it to tap it into an empty net from close range, but the ball skipped away agonisingly out of reach for the duo.
Forest haven't offered too much since their opening goal either, although the hosts have played some nice football and have looked capable of adding a second.
The striker gets to the rebound first and takes the ball around Darlow, but Fernandez slides in to deny a certain goal!
Elsewhere, Millwall have levelled things up against Plymouth and Watford lead Reading.
The striker starts the move down the right flank and continues his run as Atsu and Perez combined to pick out the striker. Rondon puts his head down and gets everything he can behind his shot, drilling it into the bottom corner.
Steele got a hand to it, but couldn't keep it out as Rondon opens his Newcastle account!
Dias is released down the left flank and plays his cross into the box which Darlow can only palm out into a dangerous area. Cash is following up and converts it, adding to his 93rd-minute equaliser from the last round!
Forest go from bemoaning the six minutes to be thankful for them, and now it is Newcastle looking to swing the pendulum back in their favour again.
Forest don't worry about that, though, and go straight up the other end to put the game to bed as Dias chips a lovely finish over the keeper and in.
What a finale to this game, just as it looked as though it might have been settled by a goal after less than two minutes!
Salomon Rondon had other ideas and appeared to have forced penalties with his 92nd-minute equaliser, but moments later Matty Cash restored Forest's lead to put them back on course for the third round.
There were more twists to come, though, and Newcastle should have had a penalty right at the death before the hosts went straight up the other end and added a third through Gil Dias.
Thank you for joining Sports Mole for tonight's thriller as Nottingham Forest dump Newcastle out of the EFL Cup for a second successive season, I will leave you with our match report, and be sure to stick around for reaction too.
From me, though, it is goodbye for now!