A defeat to Fulham in their previous league outing had been partially atoned for with a 4-0 Champions League hammering of FC Twente, but the Gunners could not afford to lose further ground.

And Robin van Persie's brace and a goal from Denilson ensured they stayed in touch with the early pace-setters.

"The improvement comes from a completely different attitude," Wenger said after the match at Emirates Stadium.

"We showed that against Twente and did it again tonight.

"The Fulham match had come at the start of the season after difficult games, including one away in the Champions League and maybe we were not ready mentally."

West Ham emulated their London rivals by making it two wins from three with a 4-1 beating of Blackburn at Upton Park.

Calum Davenport and a Christopher Samba own goal put under-fire Alan Curbishley's Hammers two goals ahead before Jason Roberts pulled one back and then missed a penalty.

Injury-time strikes from Craig Bellamy and Carlton Cole added gloss to the scoreline as Rovers boss Paul Ince endured a tough return to his old stomping ground.

Curbishley admitted it had been a "tough week" after sections of the club's support turned against him in an edgy midweek win over Macclesfield in the Carling Cup.

He added: "It's difficult with fans having a go at you after only two games but West Ham fans are second to none when they get behind the team and that's what we want. I can take any flak."

Middlesbrough are also on six points after Tuncay's late goal handed them a 2-1 win over Stoke at the Riverside.

Afonso Alves' free-kick and a Justin Hoyte own goal had left the match deadlocked, and Boro boss Gareth Southgate said: "It's our best start for a number of years and we know the team can grow together and improve together."

Everton dropped into the bottom three after a woeful 3-0 defeat to Portsmouth at Goodison Park courtesy of Jermain Defoe's double and a Glen Johnson goal.

Toffees manager David Moyes called on his experienced players to drag them out of their predicament after a trying summer for the Merseysiders.

"We've got a lot of young players in the side but it's not those players who are letting us down," the Scot said.

"There are big players in the team not playing as well as they should be."

Wigan claimed their first points of the season with a 5-0 thrashing of new boys Hull at KC Stadium.

Amr Zaki (two), Antonio Valencia, Emile Heskey and a Sam Ricketts own goal did the damage for Steve Bruce's promising side.

But the former Manchester United defender said afterwards: "We're only three games in of course but, arguably, it's the worst we've played - it sounds stupid enough but it is."

Bolton and West Brom fought out a goalless draw at the Reebok Stadium.

Baggies boss Tony Mowbray summed up the closely-contested game afterwards by saying: "I think it was a game we could easily have got three points from but we could easily have lost it as well."