Alex Song headed an 88th-minute winner as Arsenal snatched a dramatic victory to keep West Ham bottom of the table. The visitors looked on course for a hard-earned point thanks to a string of outstanding saves from Robert Green. He reacted brilliantly to repel a Cesc Fabregas shot in the first half and later thwarted Theo Walcott and Fabregas for the second time. Samir Nasri hit the bar and Walcott the post before Song nodded in Gael Clichy's cross to seal the points. The result keeps Arsenal second in the Premier League, five points behind leaders Chelsea, while West Ham stay 20th, cut three points adrift of any other team after Wolves shocked Manchester City. Arsene Wenger's side looked to have hit a brick wall as Green and the tireless Hammers defence saw off attack after attack in the second half. But their pressure eventually told thanks to Song's late intervention and Wenger's men can head into Wednesday's Champions League game at Shakhtar Donetsk in high spirits. West Ham must now regroup ahead of their trip to Birmingham next Saturday and, despite this demoralising late defeat, they deserve plenty of credit for a resilient display. Both sides arrived off the back of morale-boosting victories in the Carling Cup, but a return to league action brought with it a reminder of the current disparity between the two clubs. While financially-sound Arsenal appear well set to launch a sustained challenge for the Premier League title, cash-strapped West Ham have struggled badly in Avram Grant's first season at the helm. Having collecting just six points from their first nine matches, midfielder Valon Behrami had admitted his side were taking to the field "a little bit scared" - and a lack of belief was apparent in the early stages as they struggled to make it out of their own half. The busy Andrey Arshavin shot wide after a flowing move and it took a superb challenge from Danny Gabbidon to deny Nasri, whose corner was then headed over by Song. West Ham did well to emerge from the opening quarter unscathed and they soon settled into a tidy rhythm, looking dangerous from both set-pieces and on the counter-attack. Free-kicks by Mark Noble and Victor Obinna caused trouble, Frederic Piquionne squandered a promising opening after surging in from the right and Arsenal had to be alert following Obinna's run and cross from the left. The Gunners carved out the best chance of the first half when Song and Bacary Sagna combined to tee up Fabregas, but Green showed quick reaction to save the Spaniard's curling effort with an athletic dive to his right. Arsenal were not at their fluent best but still carved out chances and Green did well to thwart Song and Sebastien Squillaci before the break. There was a greater sense of urgency about the hosts after half-time and Nasri rattled the woodwork with a 35-yard free-kick to set the tone. West Ham were working hard to keep their opponents at bay but Nasri, Fabregas and Arshavin began to station themselves higher up the pitch in support of lone-striker Marouane Chamakh and Walcott came on for Denilson as Arsenal went all out for the win. Chamakh glanced an Arshavin free-kick straight at Green before Walcott latched on to Fabregas's sublime through-ball and watched his low strike come come back off a post. West Ham once again had Green to thank for a one-handed save from Fabregas and, with time ticking, Wenger introduced Nicklas Bendtner in place of Arshavin. Arsenal continued to press and it eventually paid off as Song rushed on to Clichy's floated ball in from the left and won the match with a close-range header. Source: BBC