French striker Olivier Giroud scored his first goal for Arsenal – and missed a penalty – as the Gunners maintained their unbeaten start to the season with a 6-1 win over League One side Coventry.
Emmanuel Frimpong, recovered from his knee injury, and Andrey Arshavin, who spent the second half of last season on loan at Zenit St Petersburg, made significant returns to the side.
Giroud beat the offside trap and latched on to a pass from Francis Coquelin's pass to open the scoring, but had his penalty saved by Joe Murphy in the Coventry goal, after Reece Brown had brought down Arshavin.
Alex Oxlade-Chamberlain got the second, before Arshavin scored on a rare start.
Theo Walcott grabbed the first of two goals before Callum Ball replied for the visitors on 78 minutes.
Ignasi Miquel got a fifth, and Walcott added another on 90 minutes.
Arsene Wenger said: "I think we did our job, in the first half we were tested defensively mainly, in the second half our offensive potential made the difference when they tired a little bit."
League Cup holders Liverpool beat West Brom 2-1 with a youthful side, both goals coming from Nuri Sahin.
16-year-old striker Jerome Sinclair came on for Samed Yesil in the 81st minute to replace Jack Robinson as Liverpool's youngest ever player.
The Reds went behind early on after Brad Jones fumbled a free-kick, allowing Gabriel Tamas to put The Baggies ahead.
Sahin levelled with a shot that sneaked under Ben Foster, before Liverpool produced a well-worked move, with winger Oussama Assaidi crossing for Sahin to tap in a winner.
Brendan Rodgers made 11 changes to the side that were beaten by Manchester United on Sunday, highlighting that his main focus is the game against Norwich, as Liverpool chase a first League win of the season.
Manchester United beat Newcastle 2-1 to set up a fourth round tie at Chelsea.
Wayne Rooney made a rerturn after his leg injury against Fulham a month ago, and Darren Fletcher was made captain on his first start in 10 months.
Anderson fired into the bottom corner just before half-time, before Tom Cleverley made it 2-0 from 18 metres with his first Manchester United goal.
Papiss Cisse was rested and came on on 61 minutes, and almost sent the match into extra time, scoring with a close-range header and hitting the bar with an overhead effort 10 minutes from time.
Javier Hernandez also hit the bar after Cisse's goal, and the hosts hung on as Newcastle finished strongly.
Tottenham Hotspur beat League One side Carlisle 3-0 with goals from Jan Vertonghen, Andros Townsend and Gylfi Sigurdsson.
Spurs will travel to Norwich in the last 16.
Vertonghen headed home Sigurdsson's free-kick just before half-time, to go into the break with the lead.
Townsend got a second in the 53rd minute, after a solo run from the halfway line, before Sigurdsson sealed the win with a header from Kyle Walker's cross.
Spurs' new £8-million signing, France international Hugo Lloris, was left out of the squad.
Norwich beat League One Doncaster to earn a home tie with Spurs in the fourth round. It is the first time the Canaries have reached the last 16 of the League Cup since 1995/96.
Alex Tettey scored on debut, repaying his managers faith with a rifled shot on 26 minutes.
Norwich went into the game without a win in the Premier League so far this season, but made a lively start with Harry Kane shooting wide and Tettey sending a 25-metre effort just over the bar.
The visitors almost forced extra time when full-back James Husband's low cross was hit towards goal by substitute David Syers, but Mark Bunn made the save.
Reading twice came back from a goal down to beat QPR 3-2.
Junior Hoilett put QPR ahead after a solo run and shot into the bottom corner.
Kaspars Gorkss headed in a leveller, before a powerful shot from Djibril Cisse's put QPR back in front.
Nicky Shorey scored with a free-kick to haul Reading level again, before Pavel Pogrebnyak flicked in the winner.
Pogrebnyak also had a penalty saved by QPR keeper Julio Cesar in injury time.