Arsene Wenger, the French alchemist, will not look back fondly on the week he turned 60. Either side of his muted celebrations on Thursday, the Arsenal manager saw his side fail to translate their dominance against AZ Alkmaar into a Champions League victory on Tuesday night, forced to settle for a draw after David Mendes da Silva's late equaliser. And Arsenal's complacent streak reared its head again this evening as the Gunners forfeited a two-goal lead at West Ham to end their four-match winning streak in the Premier League. Wenger feels he has assembled his most creative side in his 13 years as manager but they are also the most brittle. Robin van Persie scored one and created another to put Arsenal in command after 37 minutes but Alessandro Diamanti inspired an unlikely comeback by turning provider for Carlton Cole's equaliser and then converting a nerveless penalty. The result failed to end West Ham's search for their first league win of the season since the opening day but Gianfranco Zola, the Hammers manager, would surely have bitten your hand off had you offered his troubled team a draw at half-time, especially after seeing midfielder Scott Parker harshly sent-off late on for a second bookable offence. The early portents for West Ham were ominous. Van Persie engineered two chances inside the first three minutes, the second of which forced a smart near-post save from Robert Green. The Dutch forward also had justifiable claims for a penalty after his ball into the box appeared to be handled by Matthew Upson. Zola could probably have stomached his side being carved apart by Arsenal's slick interplay but what will have irked the West Ham manager was the soft nature of the two first-half goals his side conceded. The first arrived on 16 minutes when Green could only deflect an out-swinging cross from Bacary Sagna into the path of a grateful Van Persie who tapped into an empty net. Van Persie went from executioner to architect for the second on 36 minutes, with his inswinging corner headed firmly home by Gallas. Zola was entitled to expect better from a defensive set-up that included more 6ft markers than Arsenal had attackers. Gallas' clinical header was in stark contrast to a glorious chance wasted by Cole just three minutes earlier. The England striker really should have beaten Vito Mannone from six yards but he sent his header wide of the post. It was a shame Cole was so wasteful as his industry merited a goal. West Ham were booed off at half-time by their increasingly frustrated fans who must have been fearing a rout in the second half. Instead of opting for damage limitation, Zola remained true to his attacking instincts by making two positive substitutions either side of the hour mark. Diamanti, the mercurial Italian, replaced Mark Noble while Guillermo Franco, the unheralded Mexican, made way for Zavon Hines. Hines could probably count himself unlucky he did not start the match, especially given the way he terrorised Liverpool in a home match last month. Hines' exuberance will have pleased the Upton Park faithful but it earned him a yellow card for a foul on Gael Clichy just six minutes after being introduced. Yet still West Ham failed to establish a foothold in the game despite Arsenal appearing content with their two-goal lead. Wenger would have liked his side to go for the jugular but they never really had the desire to get out of third gear. Cesc Fabregas and Andrey Arshavin both tested Green with varying degrees of success after unleashing firmly-struck long-range efforts but the visitors lacked a ruthless streak. They paid a heavy price. Cole headed in the first for West Ham after Mannone could only parry a shot from Diamanti into the centre of the goal. Sensing an unlikely comeback, the home fans cranked up the noise level and they were imploring the referee, Chris Foy, to award a penalty when Gallas appeared to illegally halt a driving run from Parker. Foy ignored the pleas but wasted no time in pointing to the spot three minutes later when Alexandre Song tripped Cole in the area. Diamanti held his nerve amid the delaying tactics from the protesting visiting players to beat Mannone, his countryman, from 12 yards. West Ham's hopes of capping a remarkable comeback with a winner were hit when Parker was sent off after collecting a second yellow card. Arsenal roused themselves from their slumber to fashion a chance to win the game but Green brilliantly denied Van Persie with an instinctive save, leaving Wenger still waiting for his birthday present from his team.