Another day, another set-piece masterclass from Arsenal.

The Premier League leaders were far from their best in a tight 2-1 win against Chelsea but two goals from well-worked corner routines proved enough to return the Gunners five points clear at the summit.

Arsenal's prowess from set-pieces has been a huge part of their title challenge, having now scored 16 times from corners - three more than anyone else - and equalling the most in a single Premier League season, alongside Oldham in 1992-93, West Brom in 2016-17, and the Gunners themselves in 2023-24.

First William Saliba nodded in after Gabriel's initial header from a corner, before fellow defender Jurrien Timber met Declan Rice's delivery to power in his third league goal of the season.

As well as being clear of second-placed Manchester City - albeit having played a game more - the Gunners also have a 100% record in the Champions League, they are in the Carabao Cup final and into the FA Cup fifth round.

But questions remain about the manner in which Mikel Arteta's men are winning games.

Chris Sutton, a former title winner with Blackburn Rovers, told BBC Radio 5 Live: "Set-piece Arsenal, again. I think they are going to win it. If they get over the line - will they be the ugliest Premier League-winning team in history? The performance wasn't there."

Former Arsenal captain Patrick Vieira added on Sky Sports: "When you are top of the Champions League and Premier League table, you expect Arsenal to go forward. It was difficult for Arsenal to take chances. The expectation is higher, you expect more from Arsenal."

But Gunners boss Arteta said: "It's not ugly, you have to play the game that is there for you to play, and against Chelsea, you know exactly the game you're going to play.

"For me, it's a beautiful game to play because there is so much quality and you have to adapt so much to what they do, and they have to do the same against us, so the margins are very, very small, and the duels at the end decide these kind of games."

And ex-Everton midfielder Leon Osman told BBC Sport: "They relied on set-pieces again, as they have all season. If it's a strength, I don't see why you wouldn't utilise your strengths."

It could be a different story in the title race if the Gunners weren't so adept at scoring from free-kicks and corners.

Arsenal forward Viktor Gyokeres has started to find the net in recent weeks and is the club's top league scorer with 10, although most have come against sides lower in the table.

The next highest is Eberechi Eze on six with five coming against Spurs in two matches and Bukayo Saka, Leandro Trossard and Martin Zubimendi on five each.

That means the Gunners goals from set-pieces are vital.

In October, before the league game with Crystal Palace, Arteta said he began focusing on the importance of set-pieces in football 10 years ago, and doing that in this campaign and appointing set-piece coach Nicolas Jover from Brentford has proved him right.

Brazilian defender Gabriel is so important in the majority of the routines that Arsenal use.

He has been directly involved in 25 goals in the Premier League (20 goals, five assists), which is now the outright most by an Arsenal centre-back in the competition, reaching that total in six seasons.

The Gunners have used a number of different set-ups from corners this season, but their movement when the ball comes in is familiar.

Arsenal's players get together at the far post and when the ball is about to be delivered into the area, the players make a move in unison to get in front of the opposition goalkeeper and defenders to get a crucial first touch on the ball.

This can lead to complaints from sides who believe they are being blocked, with Chelsea also appealing heavily after Timber's winner.

Following Arsenal's 2-1 victory over Chelsea, there have now been more goals scored from corners in the Premier League this season (138 in 281 games) than in the whole of the previous campaign (135 in 380 games).

Arsenal are going to have to navigate the tension of the title race with just nine matches left in their bid to win a first league title since 2004.

And when asked by BBC Sport if they have had to go to another level with their work on set-pieces due to the work other sides are doing, Arteta agreed.

"Yes but every team is to be fair," he said. "Look where they are in terms of the amount of goals that they score.

"We hadn't scored set-pieces for a few weeks now, but we scored so many in open play.

"Today was an option to score from this kind of situation. We've done it so well and we conceded as well."

Chelsea were starting to grow into the game before Timber's crucial goal, while they needed goalkeeper David Raya to produce some excellent saves to deny the sixth-placed Blues a point.

"I didn't think there was an awful lot between the two teams, but Arsenal came out on top and at this stage of the season that's vital, isn't it?," added Arteta's former Everton team-mate Osman.

"If your strengths are pacy wide men that create things all the time, you give them the ball all the time.

"If your strength is set-pieces, you try to win set-pieces and score from them and they're very good at it, very effective.

"And ultimately that was that was the difference between the teams, but Arsenal won't care because it's another three points."

According to Osman, Arsenal can be criticised for their style of play and are often compared to title winners of the past but if they win the title, that is all that matters.

"Many people watching want to see beautiful football or purists want to see open play great goals back to front." he said.

"That's not how football's always played. Football is about being effective in both penalty areas, finding a way.

"I think whatever happens in between can be pleasing, can be enjoyable, can be exciting.

"But ultimately, it's less important than what happens in both penalty areas because that's where games are won and lost."