Republic of Ireland under 21 international Troy Parrott made his competitive debut for Tottenham, who were knocked out of the Carabao Cup away to Colchester.
The League Two side won 4-3 on penalties after a scoreless 90 minutes.
Tom Lapslie scored the winning spot-kick after Christian Eriksen and Lucas Moura missed penalties for Spurs.
Parrott played for more than an hour for Mauricio Pochettino's side, who suffered a third defeat of the season in all competitions.
Manchester City started their quest for a third successive League Cup title with a comfortable 3-0 win away to Championship outfit Preston.
Raheem Sterling got the ball rolling for Pep Guardiola's side before Gabriel Jesus doubled the lead and the game was wrapped up by half time through a Ryan Ledson own goal.
Colchester won't be the only League Two side in the draw for the fourth round. Crawley dumped Championship side Stoke out on penalties.
Sam Vokes had put the Potters in front in the 23rd minute but Nathan Ferguson equalised before half-time.
Stoke had to play the last 28 minutes with 10 men following a red card for Irish youngster Nathan Collins.
Vokes missed Stoke's first penalty and Crawley scored all five of their penalties.
Dominic Calvert-Lewin scored twice inside the first 10 minutes as Everton won 2-0 at Sheffield Wednesday to ease the pressure on manager Marco Silva.
The Toffees were coming off the back of a disappointing Premier League defeat to Sheffield United.
Arsenal's clash with Nottingham Forest was delayed by 15 minutes due to traffic but that was the only problem the Gunners encountered.
Unai Emery's side ran out 5-0 winners thanks to two goals from Gabriel Martinelli and one each from Rob Holding, Joe Willock and Reiss Nelson.
Danny Ings scored two for Southampton against Portsmouth in a 4-0 win at Fratton Park.
Ings was on target twice in the first half, the second goal coming via a lovely pass from Republic of Ireland international Michael Obafemi.
Cedric Soares and Nathan Redmond sealed the win for Ralph Hasenhuttl's side in the second half.
Danny Welbeck scored his first goal for Watford as they bounced back from Saturday's humiliating 8-0 defeat away to Manchester City.
The Hornets edged past Championship side Swansea 2-1 thanks to goals from Welbeck and Roberto Pereyra.
James Justin marked his Luton return with a debut goal for Leicester to help Brendan Rodgers side progress into the fourth round with a 4-0 win at Kenilworth Road.
Demarai Gray opened the scoring for Leicester, while Youri Tielemans and Kelechi Iheanacho wrapped up the win with two goals in the final 11 minutes.