Though the berths were booked in near-opposite fashion, Sunderland and Manchester City are the two teams set to meet on March 2, with the Capital One Cup the prize in view.
Manuel Pellegrini's side strolled past West Ham over two legs, boasting an embarrassing aggregate scoreline of 9-0 running in their favour, while Gus Poyet's men clinched a far tighter win over Manchester United, going to penalties after a 3-3 aggregate draw.
The Hammers' demoralising League Cup efforts of late mean that Sam Allardyce's team haven't got a single player featuring in the semi-finals' best XI.
Result notwithstanding, there were a fine sample of players from the other three hopefuls that impressed enough to warrant their inclusion.
Looking at both semi-final legs, read on for those XI stars who did enough to weave their way into our 4-4-2 setup.
All statistics come courtesy of WhoScored.
Costel Pantilimon features in the best XI more as a result of his inactivity more than anything else, with the Romanian having relatively little to do across his last 180 minutes of League Cup football.
That being said, the towering No. 1 is nonetheless the only goalkeeper to have kept clean sheets in both legs of his Capital One Cup semi-final legs, though, it has largely been as a result of West Ham's lack of offensive threat.
Pantilimon faced three times as many shots in need of saving in this week's trip to East London; it took his entire save tally from the two matches to four.
Regardless, he showed good communication with the rest of his back five, and he made the jobs of Joleon Lescott, Matija Nastasic, Vincent Kompany and Martin Demichelis easier as a result.
It was Phil Bardsley's pressure at the Stadium of Light that initially forced Ryan Giggs into scoring an own goal opener, ensuring that a shock win over Manchester United was on the cards.
The full-back's 119th-minute, long-range finish at Old Trafford was just the icing on the cake.
Fortunately for the right-back, Adnan Januzaj was switched over the right flank for the second leg, meaning that the man who had initially given him some defensive concerns was generally out of mind for the second match.
Bardsley succeeded in keeping Shinji Kagawa relatively quiet for the return visit to Old Trafford, all the while offering Adam Johnson a consistent option down the right flank against his former club.
As the never-ending rotation between Gael Clichy and Aleksandar Kolarov lingers on, it was the Frenchman who played the vast majority of Pellegrini's most recent League Cup trials.
Guy Demel and Matt Taylor offered the City left-back little concern in the first and second legs, respectively, meaning that the defender was given free rein in helping his team push forward.
Clichy bagged an assist in the 6-0 drubbing of the Hammers at the Etihad Stadium and followed that performance up with an outing at Upton Park that left a yellow card as the only besmirched moment of the night.
Joleon Lescott was the only Manchester City centre-back to play in both legs of his team's Capital One Cup semi-final, and the competition showed that the Englishman still has worth at the top level.
Granted, Lescott's playing alongside some superb talents, but he did manage to outshine even the likes of Kompany and Demichelis at times.
This week's trip to the English capital offered the defender a particularly big ask (no pun intended) in the shapes of Andy Carroll and Carlton Cole, but the attacking pair were left to live off of scraps thanks to Lescott's assured presence in the heart of Pellegrini's back four.
The absences of Wayne Rooney and Robin van Persie have meant that United need to look at other parts of the pitch for goals of late, and the centre-backs stepped up to the plate over the last few weeks.
In the first leg, it was Nemanja Vidic who gave the Red Devils a late lifeline, and this week saw Jonny Evans get his name on the score sheet far earlier to push his team back into the League Cup tie.
Though the Northern Irishman could have been a more reliable presence a fortnight ago, he made up for it by restraining the likes of Steven Fletcher and Fabio Borini on Wednesday evening.
Alongside Chris Smalling, Evans showed an impressive thirst to get forward but seldom left his defensive responsibilities abandoned.
He dealt with a raft of Sunderland set pieces comfortably.
Paolo Di Canio can at least take credit for concluding a wonderful piece of loan business in the shape of Ki Sung-Yueng, who has showed against United that he's capable of handling the bigger tests.
The South Korean maintained an average passing accuracy of 91 percent across the two legs and made the likes of Michael Carrick, Tom Cleverley and Darren Fletcher work to gain possession.
As his spell at Sunderland has wore on, Ki has succeeded in adding an attacking edge to his game that hasn't always been present, but it's a development that Swansea City will be as happy to see as anyone else.
Calm in possession and constantly looking to find that killer ball through unseen lines, Ki might have had more success going forward with more reliable attacking outlets ahead of him.
He scored a superb spot kick in the shootout.
Marcos Lopes was only handed 20 minutes to impress at the Etihad Stadium a fortnight ago, but a fairly comfortable cameo was followed up by a rousing 90-minute display in East London on Tuesday.
While Jesus Navas impressed on the right flank, Lopes moved about the left flank and through City's central channels at Upton Park in what was only the youngster's second start for City's first team this term.
The Portuguese Under-19 star looked assured among the glittering stars of the Citizens' line-up, crafting two superb goals for his side and thriving among big company.
Big things are to come from this starlet if his first start against Premier League opposition was anything to go by.
Having only come on for a cameo at the Stadium of Light, Adam Johnson was handed a starting role for the trip to Manchester. Gus Poyet evidently saw the damage that the winger was capable of.
It was Johnson who drew Tom Cleverley's foul in order to give Sunderland a hugely important 2-1 lead coming away from the first leg, and that momentum was carried through to Old Trafford.
For all the positives that Fabio Borini brought to the Mackems' cause, Johnson was more of a reliable threat, adding a little more end product to his play and causing the United defence a long line of problems.
Special mentions go to Samir Nasri and David Silva, who would have likely found their way into the team had they not both missed the second leg at West Ham.
Manchester United's brightest player across the two legs against the Black Cats, Adnan Januzaj again showed himself to be not just the finest of his side's young talents, but the most competent, creative asset they possess full stop.
Bardsley had a relatively fruitful time against the 18-year-old in the northeast, but Januzaj showed grand versatility in being able to shift over the right in the second leg.
There, Marcos Alonso was forced into making more than a few rash challenges on the youngster and fell victim to a stylish nutmeg at Old Trafford.
Januzaj was unfortunate not to score in the first leg and again shone as one of United's main scoring threats this week, giving his opposite man a torrid time down the flanks and producing many a marvel with his astute dribbling.
Among the most impressive things about the teenager's semi-final display came in the second leg where he stepped up to the senior plate in giving his side scoring chances from the first minute to the 120th, only failing to craft a goal for Javier Hernandez—thanks to the Mexican's poor confidence in front of goal.
However, the dynamic duo would make up for that in the last seconds of extra time, Januzaj teeing his teammate up for a dramatic 3-3 aggregate equaliser and forcing penalties.
He saw a poor penalty attempt saved in the shootout, however.
The only player in our line-up to have featured in just one leg of the semi-finals, Sergio Aguero's outing at Upton Park this week is enough to book him a spot in our best XI.
The Argentinian made his first start since returning from injury this week, scoring for the third match in a row, not to mention his first of the 2013-14 Capital One Cup campaign.
If that wasn't enough, Aguero also set up a goal for his domineering strike partner to make the score 3-0, which brings us onto out last and most impressive player of the League Cup semi-finals.
Five goals and one assist from just two matches is sufficient to see Alvaro Negredo named as our "Man of the Semi-Finals," further establishing himself as one of the Premier League's finest finishers.
Allardyce will be sick of the sight of the former Sevilla stalwart, whose hat-trick at the Etihad Stadium wasn't quite matched in Tuesday's return fixture, but it wasn't too far off.
Negredo was clinical enough to finish off most of those clear-cut opportunities thrown his way, but the Spaniard also crafted his own supply, particularly when finishing off a solo effort in the second outing.
Although Sergio Aguero may have been the undisputed first choice for Pellegrini at the time of his injury a month ago, the South American has some serious competition in Negredo should their manager ever opt to field just the one striker.