Kai Havertz came off the bench to score the only goal of the game one minute into stoppage time at the end of the tie, when it looked like a draw was on the cards.

Havertz produced a brilliant, composed finish after picking up a neat pass from fellow substitute Gabriel Martinelli.

The Gunners, meanwhile, had David Raya to thank for a number of strong saves, keeping out Maxi Araujo, Geny Catamo and Luis Suarez late on.

Arsenal also had a Martin Zubimendi goal ruled out by VAR for offsides.

It was a welcome result for Mikel Arteta's side after cup losses to Manchester city and Southampton.

The winner of the quarter-final tie will face one of Barcelona or Atletico Madrid in the semi-finals.

Speaking after the game, Arteta said on Sky Sports: "Very happy to win away from home in the quarter-finals of the Champions League against a team that have not lost at home for I don't know how long.

"I think the last time was probably in Europe as well, that shows the difficulty of it.

"When we got into the final third and we sat there, we missed the final bit. We had to be a little bit crisper, faster, more efficient to break them down when they had that block.

"We had a goal disallowed and there were two or three occasions where we were close but we lacked that final pass. In the end a magic moment from the finishers wins us the game.

"Beautiful and that's the impact you need when you get to this stage of the season. Everybody has to make an impact and they certainly did that tonight."

Sporting coach Rui Borges expressed his frustration after the defeat.

He said: "It's frustrating. It's only natural to feel a bit frustrated after the great game we played here against a top-class side.

"If you look at the 92 minutes, we had three or four clear-cut chances, whereas they had none apart from the disallowed goal. We just needed to be a bit sharper in front of goal. That's football; let's keep our heads up and believe that it’s possible.

"I believe we need to be mature and intelligent in our approach to turning the result around, bearing in mind that we're playing against a top-class side that can make the difference in the tiniest of spaces, as was the case with today’s goal.

"I'm now firmly convinced that we'll be competitive in London and that we'll see this tie through to the end."

The two sides resume hostilities in the second leg on Wednesday 15 April 2026.

Chelsea progress in Europa Conference League courtesy of Dewsbury-Hall winner in second leg