Liverpool beat Middlesbrough 14-13 in a marathon penalty shootout in the third round of the League Cup on Tuesday, after Arsenal and Everton both bowed out of the competition.
Liverpool squeezed through after Patrick Bamford had scored a penalty for Middlesbrough in the third minute of injury time at the end of extra time to give the second-tier club a dramatic 2-2 draw at Anfield.
In the all-Premier League ties, Arsenal surrendered a one-goal advantage to lose 2-1 to Southampton, Swansea beat Everton 3-0 and Stoke came from a goal down to beat Sunderland 2-1.
Liverpool started with Raheem Sterling, Adam Lallana and Lazar Markovic playing behind Rickie Lambert, who was captain for the evening on his full debut in place of the rested Steven Gerrard.
But it was 17-year-old debutant midfielder Jordan Rossiter who gave Liverpool the lead after 10 minutes, drilling in the rebound after Middlesbrough goalkeeper Jamal Blackman could only parry Lambert's initial effort.
Middlesbrough equalized in the second half when Adam Reach headed in a free kick after 62 minutes and Adam Clayton hit the post in the 85th as the visitors poured forward in a vain search for a winner before the end of regulation time.
Suso, an extra time substitute for Markovic, appeared to have secured Liverpool's route to round four when he slotted past Blackman after Adam Lallana's cross was not properly cleared in the 109th minute.
But Kolo Toure brought down Bamford in injury time after Sterling bizarrely passed the ball into a space where there was no teammate, and Bamford converted the resultant spot kick to take the game to penalties.
It proved to be the longest in the competition's history, requiring 30 spot kicks before yielding a winner.
Sterling missed his penalty in the first round of the shootout, squandering the chance to win it 5-3. Instead, it took Middlesbrough's Albert Adomah to send his second penalty wide for Liverpool to celebrate a protracted victory.
"I thought it was great quality, both teams showed great composure," Liverpool manager Brendan Rodgers said of the shootout.
"We gave away poor goals, to be honest. At the moment, we are making too many mistakes but I can't fault the character and the mentality of the players. Congratulations to Middlesbrough, I thought they were excellent. but it's great for us to get through."
Earlier, Alexis Sanchez had put Arsenal ahead with a brilliant free kick in the 14th minute at Emirates Stadium. However, Dusan Tadic leveled six minutes later with a penalty, his first goal for Southampton, after Tomas Rosicky had fouled Sadio Mane.
Defender Nathaniel Clyne then lashed in a vicious strike from long range in the 40th for Southampton's winner.
"It's disappointing because we had a good start, but we made big errors when we had the ball," Arsenal manager Arsene Wenger said.
"You have to give credit to Southampton. They are a good side and they played very well tonight. I cannot fault the attitude. The reason we lost is because of our opponent's performance. It is not the players' fault."
Sunderland lost to Stoke despite United States striker Jozy Altidore giving it the lead after 16 minutes. Defender Marc Muniesa struck twice for Stoke, either side of halftime, with his first goals for the club.
Swansea beat Everton courtesy of goals from Nathan Dyer, Gylfi Sigurdsson and Marvin Emnes, while MK Dons, which had thrashed Manchester United 4-0 in the previous round, continued its cup run with a 2-0 victory over Bradford.