Match ends, Arsenal 2, Blackpool 1.
Arsenal will play arch rivals Tottenham in the Carabao Cup quarter-finals after surviving a late fightback from League One visitors Blackpool as both sides finished the game with 10 men.
Gunners full-back Stephan Lichtsteiner slid in his first goal since joining from Juventus before teenager Emile Smith Rowe doubled the Premier League giants' lead after half-time.
Arsenal were coasting until French midfielder Matteo Guendouzi was given a second yellow card for pulling back Jordan Thompson, leaving them facing the prospect of playing the final 35 minutes with a numerical disadvantage.
Blackpool, who are mid-table in the third tier, narrowed the gap when centre-back Paudie O'Connor headed in from a corner.
That meant the game turned into a nervier finish than it should have been for Arsenal, who fielded a much-changed side which still contained several experienced stars.
However, Blackpool were also reduced to 10 men with a few minutes left to play when O'Connor was shown a straight red card for scything down substitute Pierre-Emerick Aubameyang.
O'Connor's dismissal checked Blackpool's momentum as Arsenal stretched their unbeaten run to 13 matches under new manager Unai Emery.
"We controlled a lot of moments in the match," the Spaniard said.
"At 2-0 the match is good but the red card gave more balance to them. But I think we deserved the victory."
The Gunners, who lost to Manchester City in last season's League Cup final, will host Tottenham in the last eight during the week of 17 December.
Should Emery focus on League Cup?
The debate over the importance of the League Cup in modern football has long continued, some managers moaning that the competition is a hindrance to their league ambitions, others seeing it as a great opportunity to claim silverware and build a trophy-winning culture.
Emery, who replaced long-serving manager Arsene Wenger in the summer, is likely to fit into the latter category.
The Spaniard has stressed the importance of the Carabao Cup as he looks to win a trophy in his first season at Emirates Stadium and treated the competition - and visitors Blackpool - with respect as he named a team containing seasoned internationals such as Cech, Lichsteiner, Aaron Ramsey and Danny Welbeck among his starting XI.
Youngsters like Smith Rowe and Spanish defender Julio Pleguezuelo, making his Arsenal debut at centre-back, blended youth with experience as Emery was rewarded with a solid if unspectacular victory.
Now it will be interesting to see what approach Emery takes - whether or not he decides to play more first-team regulars - when Arsenal face Spurs in the next round.
'We gave them a scare' - what they said
Blackpool manager Terry McPhillips:
"We gave them a scare and I thought the lads were terrific to a man.
"To come here - the best team in Europe at the moment with the run that they're on - and scare them is brilliant.
"The sending-off helped, obviously. That got us back in the game, though I felt that they scored from their only two chances."
Blackpool don't like a day out at Arsenal... - the stats
- Arsenal have reached the League Cup quarter-final for the third consecutive season - eliminating non-Premier League opponents in the fourth round in each of these seasons, beating Reading in 2016, Norwich in 2017 and now Blackpool
- Blackpool are winless in their last 15 away matches against Arsenal in all competitions, losing 11 and drawing four
- Guendouzi is the first Arsenal player to be sent off in the League Cup since Denilson against Blackburn in December 2007
- Lichtsteiner became the oldest player to score a competitive goal for Arsenal since Sol Campbell (aged 35 years 152 days) against Porto in February 2010
- Smith Rowe has scored in his last two appearances for Arsenal in all competitions
- O'Connor is the first player to both score and be sent off in a single League Cup match since Lewis Cook for Leeds against Doncaster in August 2015
- 29GuendouziBooked at 56mins
- 55Smith-RoweSubstituted forIwobiat 73'minutes
- 15Maitland-NilesSubstituted forTorreiraat 60'minutes
- 23WelbeckSubstituted forAubameyangat 76'minutes
- 12NottinghamSubstituted forPritchardat 65'minutes
- 5O'ConnorBooked at 84mins
- 15ThompsonBooked at 45mins
- 25GuySubstituted forO'Sullivanat 86'minutes
- 24FeeneySubstituted forCullenat 79'minutes
- David Coote
- Shots on Target
Second Half ends, Arsenal 2, Blackpool 1.
Attempt blocked. Henrikh Mkhitaryan (Arsenal) left footed shot from outside the box is blocked.
Attempt missed. John O'Sullivan (Blackpool) header from the right side of the six yard box is close, but misses to the right.
Substitution, Blackpool. John O'Sullivan replaces Callum Guy.
Paudie O'Connor (Blackpool) is shown the red card.
Pierre-Emerick Aubameyang (Arsenal) wins a free kick in the attacking half.
Foul by Paudie O'Connor (Blackpool).
Foul by Carl Jenkinson (Arsenal).
Jordan Thompson (Blackpool) wins a free kick on the left wing.
Lucas Torreira (Arsenal) wins a free kick in the attacking half.
Foul by Callum Guy (Blackpool).
Foul by Henrikh Mkhitaryan (Arsenal).
Oliver Turton (Blackpool) wins a free kick in the defensive half.
Substitution, Blackpool. Mark Cullen replaces Liam Feeney.
Corner, Arsenal. Conceded by Marc Bola.
Substitution, Arsenal. Pierre-Emerick Aubameyang replaces Danny Welbeck.
Attempt missed. Jordan Thompson (Blackpool) left footed shot from outside the box misses to the right from a direct free kick.
Hand ball by Lucas Torreira (Arsenal).
Substitution, Arsenal. Alex Iwobi replaces Emile Smith-Rowe.