Arsenal Subs: Ryan, Gabriel, Willian, Maitland-Niles, Chambers, Elneny, Willock, Nketiah, Martinelli.
Arsenal starting XI: Leno, Bellerin, Holding, Luiz, Cedric, Partey, Xhaka, Smith Rowe, Saka, Pepe, Lacazette.
Southampton Subs: Forster, Long, Redmond, Ramsay, N'Lundulu, Ferry, Jankewitz, Watts, Chauke.
Southampton starting XI: McCarthy, Valery, Stephens, Bednarek, Vokins, Armstrong, Diallo, Ward-Prowse, Walcott, Adams, Ings.
Stat: The Gunners have kept four consecutive clean sheets in the Premier League, last keeping five in a row back in January 2006.
Stat: Arsenal are looking to win three consecutive away Premier League matches for the first time since October 2018.
Stat: All seven of Southampton’s wins against Arsenal in the Premier League have been at home.
Stat: Southampton’s Theo Walcott can become the fourth former Arsenal player to score home and away against them in a Premier League season, after Kevin Campbell (2000/01), Nicolas Anelka (2002/03 & 2006/07) and Robin van Persie (2012/13).
Welcome to our live coverage of Southampton vs Arsenal from St. Mary's. Kickoff is at 8.15pm UK time in the English Premier League.
CHANCE! Bednarek gives the ball away and Xhaka sends Lacazette through on goal for Arsenal with a fine pass but McCarthy comes flying off his line for Southampton and smothers the effort.
GOAL! ARMSTRONG! Southampton are in front. Ward-Prowse fires a low cross towards Armstrong who gets strong contact on his half volley and it flashes past Leno. That's a superb training ground routine. Southampton 1-0 Arsenal.
Now Southampton threaten as Valery whips in a cross and Ings gets to the ball at the near post but he can only flick his header into Holding and out for a corner.
Saka goes past Vokins with ease on the Arsenal right and gets a cross into the box which Stephens clears on the stretch. That could be a mismatch tonight -- Southampton are missing Bertrand and at left back and Saka could really test Vokins.
Saka takes the corner for Arsenal and Holding heads wide albeit under pressure and off balance.
GOAL! PEPE! Southampton again give the ball away cheaply in their own defensive third and Xhaka slips a lovely pass into Pepe - playing on the left tonight - and the Ivorian sidefoots past McCarthy. Southampton 1-1 Arsenal.
Diallo makes a driving run through midfield for Southampton and Lacazette cynically fouls him. He is very lucky to escape a caution there.
Arsenal attack well after winning the ball and Partey finds Bellerin on the right to cross and Valery puts the ball behind nervously for a corner.
Saka delivers a cross from the right for Arsenal, Valery's header clear is weak and Cedric tries a volley which loops just wide of the far post.
Arsenal have started this game well with 58% of the ball and lots of pressure inside the Southampton half.
Che Adams drops deep for Southampton and plays a lovely pass to Walcott but the winger can't quite sort his feet out and ends up dragging his shot well wide of the post.
Bellerin is booked for Arsenal as he slides in on Armstrong and missed the ball.
Ward-Prowse takes a freekick for Southampton and his delivery is perfectly into a dangerous area but Ings' effort is with the outside of his right boot and lacks the requisite power to beat Leno.
Save! Southampton attack down the left and the cross from Vokins is perfectly onto the head of Adams but the effort is too close to Leno who shows good reflexes and pushes the shot to safety.
Southampton put together a flowing move as an Adams flick finds Ings to switch play out to Valery but the right back cuts inside and curls a left footed shot wide instead of passing to teammates in better positions.
Vokins links up well with Armstrong and the wide man tries a curling shot around Holding but he starts the effort too wide and it doesn't curl back enough to trouble Leno.
The game has taken a lull after a couple of Southampton fouls. That took the sting out of their own momentum.
Partey sends Lacazette away down the right channel for Arsenal but the striker can't find the onrushing Pepe or Saka and the opportunity is lost.
Walcott picks up the ball for Southampton and has two strikers making runs but he gets his pass all wrong.
GOAL! SAKA! Lacazette spots the Southampton defence very high up again and plays a pass through for Saka's run. McCarthy comes sprinting off his line and Saka can go around him and finish into the empty net with his right foot. That's a terrible decision by the goalkeeper. Southampton 1-2 Arsenal.
Penalty shout! Vokins challenge Lacazette and the striker goes down. VAR takes a look but correctly decides there wasn't enough contact there.
HALF TIME. Arsenal lead 2-1. Southampton went in front after three minutes through Armstrong before Pepe and Saka put Arsenal 2-1 up. The visitors have had a lot of joy against the high Saints defensive line.
The fourth official indicates two minutes of added time to be played.
The second half is underway!
Lots of midfield possession now for both teams. The first half was played at a crazy tempo, can the players keep that up?
Save! Walcott forces a good save out of Leno after Armstrong squares the ball to him for Southampton.
Smith-Rowe delivers a freekick and Southampton are relieved when Kevin Friend blows for a foul by Xhaka on Adams.
CHANCE! Xhaka finds Cedric, who slips Smith-Rowe through on goal but the midfielder's chip beats McCarthy but not Stephens who is covering behind him. The effort lacked enough power there.
Bellerin gets forward up the right for Arsenal and his cross looks bound for Lacazette but Pepe stretches for it and deflects it away from his teammate. It's very open match.
Cedric gets forward well and his low cross into the box is cleared twice by Stephens after a rebound. The former Saints man is doing well tonight on his less favoured side for Arsenal.
Wide! The Gunners threaten as Saka cuts inside on the right and fires a shot across goal which goes well wide. That move was started by some good feet by Cedric and lovely long switch of play.
Ings makes a superb run for Southampton as he bursts through gap between Partey and Bellerin and breeze past Holding but his shot is saved from point blank range by Leno and bounces back onto him and out for a goalkick. What a great dribble that was.
Southampton make their first change as Nathan Redmond comes on to replace Jake Vokins. Diallo drops into left back.
The board goes up for Martinelli to replace Pepe but the winger walks off super slowly and is yellow carded by Kevin Friend. But the change doesn't actually happen as Smith-Rowe is down injured.
Smith-Rowe goes off with Willian taking his place for Arsenal.
GOAL! LACAZETTE! Arsenal look like they've sealed the win. Cedric plays another switch of play, Saka cushions a right footed cross into the box and Lacazette slides in to finish. Southampton 1-3 Arsenal.
Southampton make a double change now as Ings and Walcott go off and
N'Lundulu and Watts come into the action -- a debut for the latter in the Premier League.
Southampton have had 68% of the ball in the second half. Arsenal have sat deeper and played more on the break as they protect the result, something they've done well.
Partey is down receiving treatment for Arsenal. He may nor be able to continue.
Arteta is not going to take a risk and he withdraws Partey and brings on Elneny.
Southampton seem to have accepted defeat now. Those two recent changes and Arsenal's third goal has taken the string out of Southampton.
Adams runs onto a loose ball after a David Luiz error but the striker's shot is blocked by Holding and then Luiz tries some weird dummy inside the box and Leno has to show really strong hands to smother a loose ball as Adams challenges.
Xhaka gives away a freekick and Ward-Prowse strikes the effort well and draws a save out of Leno. Bellerin has taken the role of lying on the floor behind the wall.
FULL TIME. Arsenal get a deserved win. They fell behind early to Southampton as Armstrong scored but Pepe, Saka and Lacazette responded with goals for Arsenal. Arteta's men managed the second half very well. Southampton 1-3 Arsenal.
The fourth official has indicated a minimum of five additional minutes to be played.
Arsenal make their final change as Willock comes on to replace Pepe.
Watts is booked for that foul on Elneny. That was a bit of a stamp.
Elneny make a clearance as Watts fouls him and it breaks to Pepe who goes past Valery and drives a shot over the bar.