West Ham 1 Arsenal 2: Sam Allardyce bemoans 'horribly wrong' decision involving Alex Song

Midfielder's shot was ruled offside during defeat to Gunners

West Ham manager Sam Allardyce believes his side must not let a "horribly wrong" offside decision derail their promising campaign after Arsenal closed in on the top four of the Barclays Premier League with a 2-1 win at Upton Park.

The Irons - who suffered a second successive defeat of the Christmas fixtures after they were beaten at leaders Chelsea on Boxing Day - looked to have got off to a flying start when former Gunners' midfielder Alex Song rifled in a 25-yard effort after just six minutes.

However, the goal was quickly ruled out by referee Neil Swarbrick, who judged three West Ham players - among them Diafra Sakho and Andy Carroll - were standing in an offside position in front of goalkeeper Wojciech Szczesny.

Arsenal recovered to net twice just before half-time through a penalty from Santi Cazorla and Danny Welbeck's close-range finish.

Although Cheikhou Kouyate reduced the deficit at the start of the second half, West Ham were unable to conjure an equaliser, despite plenty of pressure, but also had goalkeeper Adrian to thank for denying Arsenal on the counter-attack several times.

The Gunners leapfrogged the Irons to go level on points with fourth-placed Southampton, whom they play on New Year's Day.

West Ham are now sixth, but Allardyce is expecting a response when strugglers West Brom are the next visitors to east London.

"We have only lost two, not five, and we want to bounce back against West Brom," said Allardyce, whose side were beaten at home for the first time since August 30.

"I am pleased with the performance, the application, the commitment and the attitude and quality from the players. It is sad for them they didn't get the result."

Allardyce continued: "If we'd been allowed that goal, we wouldn't have lost. We would have kicked on and Arsenal would have found life very difficult.

"I have not spoken to the ref because I don't see any point in confronting him when you know you're 100 per cent right and he hasn't had the visuals. You can't get anything out of telling him how wrong he's been.

"Going on what we were told at the start of the season, they got it horribly wrong. He (Sakho) wasn't in the eye-line of the keeper. He didn't touch the ball.

"Yes he was offside, but we've seen so many of those allowed as goals. I've not seen one 'not given'.

"Can you tell me what is an offside? Now I'm totally and utterly confused and bewildered. There are far too many inconsistencies."

Arsenal will again be without suspended forward Olivier Giroud at Southampton.

Gunners boss Arsene Wenger accepts the Christmas fixtures have tested a squad already depleted by injury.

"We knew before the game we would have to dig deep because we were jaded, but we did that," he said.

"When they came back to 2-1, we had five or six chances on counter-attacks that we couldn't take, but overall everybody did the job very well, from the 'keeper to up front."

Wenger added: "It's vital to re-establish ourselves in the top four. We have done it for 17 years, so we are entitled to at least believe we can do it, but it's all to do because everybody fights very hard for it."

PA