Manchester United beat Arsenal 1-0 to line up a League Cup semi-final with Chelsea, while Liverpool will take on Watford after a 4-3 penalty shootout win over Tottenham Hotspur on Wednesday.
United's David Bellion scored after less than 20 seconds at Old Trafford in a tense and sometimes ill-tempered game between two second-string sides.
Another French forward, Florent Sinama-Pongolle, was Liverpool's man of the night, converting an extra-time penalty to make it 1-1 after a Jermain Defoe strike, and then scoring the decisive final spot-kick of the shootout.
The semi-finals will be played over two legs in January, with the final at Cardiff's Millennium Stadium on February 27.
United's win came five weeks after their first team ended Arsenal's record 49-match unbeaten league run at Old Trafford, triggering a collapse in form from which the champions have yet to recover.
October's 2-0 victory also led to the 'Battle of the Buffet' in which snacks were reportedly thrown at United manager Alex Ferguson in the players' tunnel, adding to a long-standing enmity between the two sides.
The latest encounter swung United's way after kickoff when Bellion's seemingly harmless shot straight at Manuel Almunia bounced off the Spanish keeper's knee and into the net.
Arsenal, fielding six teenagers and four other outfield players under the age of 22, struggled to respond and could easily have been 2-0 down after a Kieran Richardson shot which Almunia blocked.
PLAYERS TUSSLE
Solid at the back, United kept up the pressure after the break, with Arsenal's Dutch forward Robin Van Persie and Richardson being booked after an ugly challenge and a retaliation.
United manager Alex Ferguson told Sky Sports: "I was looking for more in the second half. In the first half we played very well and could have been three or four up. In the second, we didn't have the same penetration."
As for the incident involving Richardson, he said: "I think the FA will have to have a look at that. Van Persie definitely swung an arm at the boy."
Arsenal manager Arsene Wenger said: "We were caught with a bit of inexperience at the start, being not really ready and it was 1-0.
"Overall, I think they have done very well. It was a very, very young side but with some great players in there. Even if I'm disappointed we lost, I'm positive because I got some good news for the club."
United's win teed up a re-match with the Premier League leaders Chelsea, who beat them 1-0 at Stamford Bridge on the opening day of the season.
Spurs, beaten on penalties at this stage last season by Middlesbrough, were almost at full-strength against a second string Liverpool and led through substitute Defoe's strike on 108 minutes.
But Mali international striker Frederic Kanoute, one of two Spurs players with Robbie Keane to hit the woodwork over 90 minutes, gave away the penalty converted by Sinama-Pongolle in the 117th minute.
Kanoute, along with Michael Brown, then missed his penalty in the shootout.
Liverpool boss Rafael Benitez, whose club have won a record seven League Cups, said: "All the players who played today are very, very important for the future and they all played well."
Spurs boss Martin Jol said of Kanoute's handball: "It was very unfortunate and maybe unforgivable...I couldn't understand it, nobody at the stadium could. But he did it and it cost us the game."