Sam Allardyce said a lack of quality finishing was the only reason his West Ham United side did not achieve a positive result against Arsenal.

The Hammers pushed the Gunners all the way in Saturday's Barclays Premier League derby at the Boleyn Ground, taking the lead through Mohamed Diame's first-half special, only for two goals in the final 13 minutes to see Arsenal run out 3-1 winners.

While the visitors controlled possession for the most part in the early stages, West Ham were organised and resolute. Their reward came on 21 minutes when Diame spun, beat Aaron Ramsey and shot high into Vito Mannone's top right-hand corner to send the Boleyn Ground wild.

Arsenal probed for an opening, but it took a loose pass from goalscorer Diame to allow Lukas Podolski the time and space to cross for Olivier Giroud, who converted his first Premier League goal with an expertly-taken volley four minutes before half-time. Even then, Kevin Nolan came within a yard or two of putting his side back in front just before the break.

West Ham started the better after the interval, overcoming the loss of Ricardo Vaz Te to a dislocated shoulder and Guy Demel to a thigh injury to create another fine chance, only for Andy Carroll to head Matt Jarvis's cross just wide of the gaping net.

Arsenal's second goal also came from a turnover of possession. When Diame's cross was blocked, the Gunners raced 80 yards upfield before substitute Theo Walcott slotted calmly past Jussi Jaaskelainen. After Nolan had shot uncharacteristically over from 14 yards, Spain midfielder Santi Cazorla rubbed salt into the West Ham wounds, collecting a loose ball before lashing an unstoppable drive high into Jaaskelainen's goal.

When asked if the final scoreline had been harsh on his side, Big Sam pointed to Arsenal's greater quality in front of goal as the main reason for their victory.

"It was probably harsh, but that's Arsenal for you - if you don't take advantage of your chances when you get them then they will punish you and they certainly punished us towards the end of the game," said the manager.

"Obviously the disappointing thing from our point of view was actually getting our noses in front and finally ending up losing at home. It was a great team we were playing against and we've experienced how difficult it is to play against the likes of Arsenal, which is something we need to remember when we come across the likes of Chelsea, Manchester United, Newcastle and Tottenham.

"We did really, really well and, of course, needed to finish the chances when we got them. We did with the first one - Mo's goal was brilliant - but then there was one just before half-time when Kevin couldn't quite dig it out from Mark Noble's free-kick, and then in the second half Kevin has had two golden chances.

"The first one he has either got to just hit it or square it for Matt Jarvis, but instead he decided to come in on his left foot and lost it. That was a brilliant chance against an Arsenal team playing so well. Kevin also had a shot with his left foot from the edge of the box and he normally doesn't miss those, as we know.

"Then Andy has had his header. The 'keeper has come and thought he could catch it and Andy has outjumped him and won the header and the goal was open and free and unfortunately the ball dropped the wrong side of the post. We'll look back at those and think that, at one-one, that would have put us in front."

Aside from the lack of clinical finishing, Big Sam also lamented the nature of Walcott's goal, which stemmed from a Diame cross that was cut out inside the Arsenal penalty area.

"Mo has done ever so well to wriggle his way down the left-hand side but then he hasn't picked the right pass out and his cross has hit an Arsenal player. They played one pass forward and within five seconds Walcott has put the ball in our net. That was a real killer for us.

"I don't think there was anything we could do about the third goal. Cazorla has hit a brilliant strike.

"We will be disappointed with how we've lost it but they are a very good team and we've tried our best. The good thing is that we've created some reallty good chances against a very good team but we didn't take them. It was critical at the stage of the game because it would have put us back in front.

"I was really pleased with the fantastic goal we did score but disappointed there was nothing at the end of it."

Extra disappointment came in the shape of injuries to Vaz Te, Demel and Winston Reid.

"I don't think we'll have them back in two weeks - I think they'll be out for a little bit longer than that by the looks of their injuries. Certainly Ricardo is a big blow because it ilooks like a dislocated shoulder and that's anything from eight to twelve weeks.

"I think Guy Demel has pulled a thigh muscle and that could be four weeks and Winston Reid had a back spasm and we couldn't bring him off because we'd used all of our substitutes and had nobody else to bring on.

With eleven points collected from seven matches and a winnable home game against Southampton up next on 20 October, it is not all doom and gloom in east London as summer makes way for autumn.

"There is cause for optimism because we have started the season very well. It was a disappointing result on Saturday but not a disappointing performance. We've only put in one poor performance in seven league games and that was at Swansea.

"We can't linger on this disappointment. We have to get back to winning ways in two weeks' time. That will be the big test for us now - can we bounce back after a defeat and can we beat Southampton and make sure we get three points on the board again."