Arsenal extended their perfect Premier League start to four wins from four matches on Saturday, grinding out a 2-0 victory at Sunderland's Stadium of Light to move three points clear at the top of the table — though manager Mikel Arteta left the ground as much angry as satisfied. Goals from summer signing Bruno Guimaraes and Bukayo Saka secured the defending champions' 12th point of the season, but the result was overshadowed by a controversial penalty awarded against Arsenal that Arteta described as "unacceptable."

The match turned on a sequence of events just before the hour mark. Sunderland, who were competitive throughout and made life difficult for their more illustrious opponents, won a penalty when referee John Brooks penalised Ezri Konsa for pulling down Dan Ballard from a corner. But goalkeeper David Raya saved Enzo Le Fee's spot-kick, and two minutes later Guimaraes — introduced as a halftime substitute — curled a right-footed shot into the top corner after receiving a pass from Declan Rice. The Brazilian midfielder, who joined Arsenal from Newcastle in the summer, celebrated pointedly in front of the home crowd, cupping his ears after they had booed him; Sunderland and Newcastle are fierce rivals in England's North-East. Saka then sealed the result deep in stoppage time, converting from the spot after Reinildo Mandava fouled him — a challenge that also earned Mandava a red card.

Arteta was unapologetic in his criticism of the penalty decision. "It's unacceptable at this level. This changes the course of the season, the championship," he said. "I've been in football for almost 27 or 28 years. It's not a penalty in any case, in any game, in any context, in any league." The Premier League confirmed the penalty was awarded for holding. Despite his frustration, Arteta acknowledged Arsenal had needed resilience to claim all three points, praising Raya's save as decisive and crediting Sunderland for making it so difficult.

The wider Premier League picture on Saturday worked in Arsenal's favour. Liverpool, who have assembled an attack costing well over half a billion dollars including British record signing Alexander Isak and France winger Bradley Barcola, were held to a goalless draw at home by a Fulham side that had been pointless going into the game. Chelsea were pegged back to a 2-2 draw by newly promoted Hull City at Stamford Bridge, with defensive fragility again on display. Tottenham, who spent more than 400 million dollars in the summer transfer window, remained without a Premier League goal after a 0-0 home draw with Everton — more than six hours of football without finding the net. Manchester City, the only other side with a 100 percent record, can close the gap to zero points if they beat Manchester United on Sunday.

Arsenal's start is all the more striking given that it comes with clean sheets in four of their five competitive matches, including a Champions League win at Napoli during the week. For Sunderland, a club based in the city of the same name in northeast England and playing in the Premier League after years in the lower divisions, the narrow defeat will nonetheless offer encouragement: they tested a title-winning side and came close to taking something from the game. For Arsenal, the priority now will be maintaining momentum — and, if Arteta has his way, persuading referees to raise their standards.