Match ends, Portsmouth 0, Arsenal 2.
Arsenal manager Mikel Arteta said the club's young players are "worth the risk" after his youthful team beat League One Portsmouth at a noisy Fratton Park to reach the FA Cup quarter-finals.
Arteta named a side with six players aged 20 or under and they looked in control, especially in the second half, as they beat a team which had not lost in 19 home games and had won their previous 10.
Pompey played well in the first half but trailed to Sokratis Papastathopoulos' volley from Reiss Nelson's cross just before the break.
Eddie Nketiah bundled home from close range from another Nelson cross to wrap up the victory six minutes after the restart.
Pompey's only shot on target came in the second half, with substitute Ronan Curtis' effort saved.
"I'm really pleased with them," Arteta told BBC Sport. "I'm enjoying working with the players. They deserve a chance. It's always a risk but they're worth the risk.
"It was a great atmosphere and Portsmouth made it difficult. We knew we'd have moments we could suffer but we reacted and got control of the game. We got two goals and could have had a few more."
The other fifth-round ties are on Tuesday, Wednesday and Thursday. The quarter-final draw is on BBC One on Wednesday at 21:50 GMT after Sheffield Wednesday v Manchester City.
Gunners keep trophy hopes alive
Arsenal came into this game on the back of their shock Europa League exit to Olympiakos on Thursday.
Arteta - slightly surprisingly - made nine changes, with several fringe players starting, and defender Pablo Mari making his debut, despite the FA Cup being the only hope of silverware for the record 13-time winners.
They lost Lucas Torreira to injury in the first half, the midfielder taken off on a stretcher after a tough but fair sliding tackle by James Bolton.
That was their only negative from the game at Fratton Park, though.
Left-back Bukayo Saka - one of the two players to keep their place from Thursday's defeat - forced a save and Gabriel Martinelli, also 18, headed over the bar.
Sokratis opened the scoring with a wonderful volley from Nelson's right-wing cross.
And Nketiah scored his third goal since his loan spell at Leeds was cut short when he controlled Nelson's cross before rifling into the roof of the net from close range.
From that point on Arsenal looked comfortable. They extended their unbeaten run against Portsmouth to 22 games and have not lost to them since 1958.
"There is a long way to go [in the FA Cup]," said Arteta. "But we're on the right path. We'll see what happens in the draw. We'll keep going because we love this competition."
Portsmouth can focus on promotion
This was something of a bonus match for Portsmouth, who are third in League One and pushing for promotion.
That was reflected by their starting line-up with their two top scorers - Curtis and John Marquis - and captain Tom Naylor on the bench.
Kenny Jackett's side played well in the first half, with eight shots - but Curtis' 73rd-minute effort from the corner of the box was their only one on target.
Arguably this was not even their biggest game of the week - they go to seventh-placed Peterborough on Saturday, with the clubs separated by only three points.
They also have a Wembley trip to come, against Salford City in the EFL Trophy final on 5 April.
"In terms of winning the game, getting the first goal would have been key and with the pressure we had, we needed one," said Jackett.
"But after their second they dominated and it would have been a goal out of nothing from us. Then realistically we were playing damage limitation. My players didn't buckle, kept going and that was good."
Match stats - Arsenal unbeaten away under Arteta
- Arsenal have gone 11 games without defeat on the road since a 2-0 loss at Leicester in Unai Emery's last away game in charge.
- The Gunners have reached the quarter-finals of the FA Cup in five of the past seven seasons but for the first time since 2016-17, when they won the cup.
- This was Portsmouth's first defeat at Fratton Park since September 2019 against Southampton in the Carabao Cup (4-0), ending their 19-game unbeaten run at home.
- Sokratis is the first Greek to score in the FA Cup since Apostolos Vellios for Nottingham Forest against Hull in January 2018.
- Sokratis has scored with all three of his shots on target for Arsenal this season.
- Eddie Nketiah has scored three goals in his past four starts for Arsenal, with two of those coming in the FA Cup.
- Reiss Nelson has been directly involved in five goals in his last eight starts for Arsenal (two goals and three assists).
- 24McGeehanBooked at 39mins
- 26EvansSubstituted forCannonat 74'minutes
- 19HarnessSubstituted forCurtisat 67'minutes
- 22HarrisonSubstituted forMarquisat 67'minutes
- 23David Luiz
- 29GuendouziBooked at 35mins
- 11TorreiraSubstituted forCeballosat 16'minutes
- 24NelsonSubstituted forMaitland-Nilesat 90+1'minutes
- 28WillockSubstituted forXhakaat 87'minutes
- Mike Dean
- Shots on Target
Second Half ends, Portsmouth 0, Arsenal 2.
Foul by Gabriel Martinelli (Arsenal).
Ryan Williams (Portsmouth) wins a free kick on the right wing.
Substitution, Arsenal. Ainsley Maitland-Niles replaces Reiss Nelson.
Corner, Arsenal. Conceded by Ross McCrorie.
Pablo Marí (Arsenal) wins a free kick in the defensive half.
Foul by Andrew Cannon (Portsmouth).
Attempt blocked. Dani Ceballos (Arsenal) right footed shot from outside the box is blocked. Assisted by Eddie Nketiah.
Substitution, Arsenal. Granit Xhaka replaces Joseph Willock.
Attempt missed. Andrew Cannon (Portsmouth) right footed shot from the right side of the box is close, but misses the top right corner.
Offside, Arsenal. Bukayo Saka tries a through ball, but Eddie Nketiah is caught offside.
Corner, Arsenal. Conceded by Steve Seddon.
Attempt missed. Pablo Marí (Arsenal) left footed shot from the centre of the box is close, but misses to the left following a corner.
Attempt blocked. David Luiz (Arsenal) left footed shot from the centre of the box is blocked. Assisted by Reiss Nelson with a cross.
Corner, Arsenal. Conceded by Alex Bass.
Attempt saved. Bukayo Saka (Arsenal) left footed shot from the left side of the box is saved in the top centre of the goal. Assisted by Dani Ceballos.
Substitution, Portsmouth. Andrew Cannon replaces Gareth Evans.
Attempt saved. Ronan Curtis (Portsmouth) right footed shot from a difficult angle and long range on the left is saved in the bottom right corner. Assisted by Alex Bass.
Dani Ceballos (Arsenal) wins a free kick in the defensive half.