Fulham - 0 Arsenal - 3: Mark Halsey will have been tossing and turning in his sleep last night as he awaited the verdict on an erratic refereeing performance that saw him change his mind about giving a penalty to Fulham, deny Arsenal a penalty and then rule out a goal for the home side involving a push that only he saw.

Keith Hackett, the manager of the referees' select group, said he would wait until he had analysed Halsey's conduct on Prozone, the computer package that breaks down performance levels, and had received various reports on the game before talking to the referee today. Hackett has already suspended Andy D'Urso for 28 days from the Premier League list this season for failing to send off Blackburn's Barry Ferguson after booking him twice; Halsey must be awaiting his fate with some trepidation. It seems likely from Hackett's comments, however, that he will escape with censure rather than a ban.

The controversy arose in the 31st minute when Arsenal's Ashley Cole appeared to bring down Andy Cole in the penalty area. The referee pointed to the spot, only to change his mind after protests by the players. He then consulted his assistant and spoke to both captains before ordering a drop ball which he bounced into the Arsenal goalkeeper Jens Lehmann's hands.

Fulham's fans were furious and the weekend media were unrestrained. "Anarchy," screamed the News of the World, while Gary Lineker suggested on Match Of The Day that Halsey's decision gave a licence to players to protest at decisions in the hope of the referee overturning them.

Halsey should at least be commended for explaining his actions afterwards. "The player reaction put a doubt in my mind. I've got to be honest, I made a mistake (in giving the penalty)," he admitted.

Such honesty left Hackett with a headache that he was unsure how to resolve yesterday. He has encouraged more openness among referees this season, believing that they should be seen to be as accountable as managers and players when things go wrong, but he is keen that they should only do so when explaining decisions based on the laws of the game rather than, say, intuition.

"I'm surprised that he came out and explained a decision that doesn't involve the law," Hackett said. "What really concerns me is his comment explaining the players' reaction. These things should not influence a referee's decision.

"The Premier League observer will be consulting with the managers and Mark will be putting in a report and I've got to wait for the reports."

Fulham manager Chris Coleman was making no secret of what would be in his. "He was crap. He said that he disallowed the penalty because of the reaction of my players and the Arsenal players. Did anyone see my players ask him not to give a penalty?"

Referees were easy targets over the weekend and, as Halsey is arguably the Premiership's best, it would be unfair to condemn him after a single off-day. In his defence, replays showed Andy Cole trying to get a shot away before Ashley Cole clattered into him, scuffing the ball towards the hands of Lehmann.

Where Halsey did get it wrong was in the incidents that followed. In the 41st minute he was a long way behind play when Moritz Volz crunched into the back of Thierry Henry's ankle and refused to award a penalty. Then, when Collins John rose well to head the ball past Lehmann, Halsey disallowed the goal for a questionable push.

The referee looked unnerved as stewards escorted him from the pitch but he regained his equilibrium in the second half - as did the champions, whose players seemed weary after a week of international duty, particularly returning captain Patrick Vieira.

The introduction on the hour of Jose Reyes for Robert Pires did the trick, three goals in nine minutes helping Arsenal extend their unbeaten run to 45 games and put clear daylight between themselves and Chelsea at the top of the league table.

First Reyes instigated the move that allowed Freddie Ljungberg to score smartly, before the Gunners persuaded Zat Knight to toe-poke an own-goal. Reyes then scored himself after a sumptuous pass from Dennis Bergkamp.

It left Arsenal looking good for tomorrow night's Champions League encounter with PSV Eindhoven.

"We have the momentum," said Wenger.