Brazilian forward Julio Baptista scored four goals as Arsenal thumped Liverpool 6-3 in their League Cup quarter-final at Anfield on Tuesday, three days after knocking them out of the FA Cup on the same ground.
Both teams made nine changes from Saturday's lineups but it was the callow Arsenal side that swept into a 5-1 lead early in the second half thanks to a hat-trick from Baptista.
Steven Gerrard inspired a fight back to 5-3 with a wonderful volley but Liverpool's late charge was ended by a fourth for Baptista, who had managed only one previous goal since his August arrival from Real Madrid.
The stunning victory earned Arsenal a semi-final meeting with north London rivals Tottenham Hotspur and left manager Arsene Wenger purring.
"I thought we had the chance to qualify but you don't expect that," Wenger told Sky Sports.
"There is an accepted character inside the club now in how we want to play the game. A great attitude and great togetherness."
Of Baptista's special night after a difficult first five months in London, he added: "I always believed it was in there - it takes time to adapt to English football.
It was the first time Liverpool had conceded six goals at home for 76 years and their woeful night was made worse by serious-looking injuries to Chile winger Mark Gonzalez and his replacement Luis Garcia.
"There was a lot of bad news at the same time," said manager Rafael Benitez.
"They [Arsenal] had four attempts in the first half and scored four goals. We have to try to forget it as soon as possible and think about Watford [in the Premier League on Saturday]," he added.
Arsenal's 27th-minute opener came out of nothing as centre back Kolo Toure launched a long ball down the middle.
Jeremie Aliadiere, who was an impressive and willing runner all night, brought it down well and beat stand-in goalkeeper Jerzy Dudek at the second attempt.
Robbie Fowler cleverly backheeled the equaliser six minutes later but Arsenal regained the lead five minutes before halftime when Baptista left Dudek helpless when he sent a 25-metre free kick over the wall and into the top right corner.
Alexandre Song bundled in Arsenal's third goal after Dudek failed to reach a cross and Baptista put the fourth into an open net, both goals coming in first-half injury time.
Liverpool were booed off at the break but the crowd got a lift 10 minutes after the restart when Dudek saved a Baptista penalty.
The Brazilian's disappointment lasted all of five minutes though as he completed his hat-trick with a low drive from outside the box to make it 5-1.
Gerrard crashed in a superb volley from the edge of the area in the 68th and then had a free kick touched on to the bar by Manuel Almunia before Sami Hyypia got Liverpool's third 10 minutes from time.
However, great work by Aliadiere set up Baptista for a simple fourth four minutes later to complete the scoring.
The first leg of the semi-final will be White Hart Lane on January 24 with the return at the Emirates Stadium on January 30. Wenger said he would continue with the youngsters for those games as he seeks the domestic trophy still to elude him.
The first leg of the other semi-final is on Wednesday when league champions Chelsea visit fourth division Wycombe Wanderers, who have already knocked out Premier League Charlton Athletic.