Arsenal's title credentials were enhanced with a battling 2-0 win at West Ham.
Robin van Persie believes this result proves the Gunners are serious title contenders.
"I think this proves we have the resilience to challenge for the league, yes, because we scored a goal after more than 70 minutes and it was a tough game," the 25-year-old told the Evening Standard
"They had their chances in the first half with (Craig) Bellamy and a few others. If you win this game at 2-0 at the end, it is a great job.
"The win was really important - we knew that before because at half time we knew Chelsea lost 1-0 and of course Man United had a draw so it was really important to get back and make some steps up the table.
"It was not easy. They played very well, especially in the first half-an-hour - they were all over the place. But we knew somehow we would get chances, especially in the second half because they gave everything in the first.
"This is what we said to each other at half-time, just keep the belief high and this is what we did. It was a big, big win for us - a massive win."