Arsenal ground out a 2-0 victory at Sunderland to claim a ninth consecutive Premier League win — a run not seen from the Gunners since the Invincibles season of 2003-04. Yet the margin of victory could have been far slimmer had a pivotal 121-second passage of play gone differently.

The moment the match turned

With just under an hour played and Sunderland pressing hard, referee John Brooks awarded the hosts a penalty after Ezri Konsa and Dan Ballard clashed at a corner. The decision divided opinion sharply. Manager Mikel Arteta was incensed, arguing that Ballard had thrown himself to the ground in what he described as a judo-style fall, and that Konsa was blameless.

"It's a judo roll from the opponent. Ezri [Konsa] does nothing. Just watch it," Arteta told BBC Match of the Day. "We have a lot of cameras and VAR, we have to take responsibility to protect the game. Today the game was unprotected and it could have cost us the game and the momentum — which is a really, really serious thing."

Arteta, who had already been booked in the first half for repeatedly leaving his technical area, went further in his post-match media conference. "This should never happen, it's not fair, and I am sad, very sad, in that sense," he said. "It's not acceptable, I've watched it 20 times and can't think of why it was given."

Former Wales defender Ashley Williams backed Arteta's reading of the situation. "It's absolutely not a penalty. Konsa's shoulder is pulled down by Ballard and he lands on top — it's like a perfect toss in judo. Very clever by Ballard, but in no way a penalty," Williams said on BBC Match of the Day.

Others were less sympathetic. "With the new laws trying to get rid of the grappling, Konsa is all over Ballard," former England midfielder Karen Carney noted on TNT Sports. Former Arsenal defender Martin Keown agreed the law was clear: "Ballard was holding Konsa's arm but you run the risk. They want to stamp down on it so there is no point arguing about it."

Raya's brilliance changes everything

Whatever the rights and wrongs of the decision, it was David Raya who settled the argument. The Arsenal goalkeeper — only making his second Premier League penalty save — flung himself full-length to tip Enzo Le Fee's effort on to the post. The ball stayed out, and within two minutes Arsenal had flipped the scoreline in their favour.

Former Brentford manager Thomas Frank, the man who originally signed Raya, was effusive. "This penalty save is exceptional. He gets out so quick. For me he's the best goalkeeper in the Premier League and one of the best in the world," Frank told BBC Match of the Day. Keown added: "He is very important to Arsenal and what they achieve. He was magnificent and doesn't get the credit he deserves."

Arsenal have now kept five clean sheets in six matches across all competitions this season, including in all three away fixtures — a continuation of the defensive solidity that underpinned last season's title triumph.

Guimaraes announces himself

Moments after Raya's stop, substitute Bruno Guimaraes smashed in the opener off the underside of the crossbar. He then added a curling strike from the edge of the penalty area for the second — a goal of the season contender that announced him emphatically to the Arsenal faithful.

The £75 million summer signing from Newcastle had endured a difficult beginning to his Arsenal career, failing to start a single match since the Community Shield following a minor hamstring injury. His performance at the Stadium of Light was anything but tentative.

"It was a beautiful goal. Everyone knows my past — I had an amazing history at Newcastle," Guimaraes told TNT Sports. "But now I'm trying to create a new history here and I start with the right foot."

Keown captured the significance of the performance: "That goal is about personality and character. It was him saying: I am going to make my mark at this football club. Boy did he shut the crowd up — a class player, going to the next level."

Arsenal left the north-east of England battered, briefly threatened, but ultimately unbowed — nine wins on the bounce and still hunting.