Arsenal maintained their place at the top of the Premier League with a controlled victory over West Ham.
Van Persie's goal was the difference between the sides
Robin van Persie scored the only goal of the game when he rose at the far post to nod in Alexander Hleb's centre.
Hleb was later carried off after a bad tackle by Mark Noble, but Arsenal continued to dominate the match.
Van Persie was denied a second when Robert Green tipped his shot onto the post, while West Ham's Dean Ashton had a goal-bound header hacked away.
After the opening 45, when a shot on the turn that went over was his most notable contribution, Ashton provided an increasingly stern test for Arsenal's back four.
Arsenal, far short of the champagne football of recent weeks, appeared to be playing within themselves.
However, in-form striker Emmanuel Adebayor almost scored with the Gunners' first attack when he fizzed a low shot just wide of the post.
And on 13 minutes Adebayor was heavily involved in the opening goal when he held the ball up before laying it off for Hleb to cross and Van Persie to finish the move.
Other than that, there was little to get excited about it the opening half.
Perhaps it was frustration that led to Lee Bowyer crunching two-footed into Matthieu Flamini and then Noble doing the same to Hleb. Both were booked.
Whereas Flamini shook off his knock, Hleb's match was over and he was replaced by Emmanuel Eboue.
West Ham lost a player, too, with Scott Parker failing to make it out for the second half after suffering knee damage in a challenge with Flamini. Hayden Mullins took his place.
Nine minutes after the break, Arsenal came close to doubling their advantage when Van Persie let fly from the edge of the area but Green managed to divert the effort onto his post.
It had the effect of waking West Ham from their slumber and Ashton should have done better with a free header when an equaliser seemed inevitable, allowing Manuel Almunia to save easily.
Two minutes later former Gunner Freddie Ljungberg thought he had restored parity when he slotted in but his goal was ruled out for offside.
More goalmouth action followed as Adebayor had a low shot pushed away by Green, Ashton sent a drive skidding wide and Adebayor shot tamely after good work by Abou Diaby.
Then Diaby shot just over from the edge of the box and Gael Clichy's low strike had Green scrambling and at full stretch.
West Ham put Arsenal under pressure for a spell, with Ashton a threat in the air.
With 10 minutes remaining, Arsenal lost Adebayor to what looked like a hamstring injury.
And the Gunners would have lost two points as well had Van Persie not been on hand to clear Ashton's header off the line shortly after.
West Ham manager Alan Curbishley on Freddie Ljungberg's disallowed goal:
"I think he was definitely onside when he scored. But they are tight things and we didn't get it. Had we got it, it was all to play for.
"From then we were sailing close to the wind to get ourselves in the game.
"However, I thought Dean Ashton might have scored with a header to get us back in the game."
Arsenal boss Arsene Wenger:
"We have had a problem taking points at Upton Park recently. We had to take our chances and overall we deserved the victory.
"It was a good test to defend a 1-0 advantage and not to make mistakes. I believe we did that very well.
"We have matured, we have more belief and we are really hungry. The players show a pleasing solidarity."
West Ham: Green, Neill, Ferdinand (Gabbidon 48), Upson, McCartney, Bowyer (Boa Morte 83), Parker (Mullins 46), Noble, Ljungberg, Ashton, Camara.
Subs Not Used: Wright, Cole.
Booked: Bowyer, Noble.
Arsenal: Almunia, Sagna, Toure, Senderos, Clichy, Hleb (Eboue 31), Fabregas, Flamini, Diaby, Adebayor (Silva 79), Van Persie (Bendtner 88).
Subs Not Used: Fabianski, Denilson.
Booked: Flamini, Eboue.
Goals: Van Persie 13.
Ref: Alan Wiley (Staffordshire).