Arsenal ended their goal drought within four minutes of kick-off at The Hawthorns - and although West Bromwich Albion responded in kind just two minutes later, the Gunners found another couple of goals to show for their 60 per cent possession, and went in at the break 3-1 ahead with their spirits lifted in the uphill struggle to catch Aston Villa and break back into the coveted top four positions.
Arsene Wenger made four changes from the team held to a fourth consecutive goalless draw by Fulham on Saturday, Johan Djourou replacing the injured William Gallas in defence, and Robin van Persie, Carlos Vela and Abou Diaby dropping to the bench in favour of Alex Song, Nicklas Bendtner and Emmanuel Eboue.
West Brom were without Borja Valero and ineligible Arsenal loanee Jay Simpson, but had Jonathan Greening back and Luke Moore in attack.
If the decision to rest top scorer Robin van Persie seemed a strange one, as Arsenal sought their first league goal since 28 January, it was quickly vindicated when his replacement, Nicklas Bendtner, broke their dismal scoreless sequence as early as the fourth minute.
Arsenal won a corner which was cleared only as far as Denilson, who played it out wide to the unmarked Bendtner. The big Dane cut inside and curled a low shot beyond Scott Carson for the Gunners' first league goal in 364 minutes of play.
But if Arsenal were relieved, they were soon back in apprehensive mode when the Baggies equalised two minutes later.
Albion were awarded a free-kick when Johan Djourou fouled Luke Moore about 25 yards from goal. Chris Brunt somehow found a way through the wall with his shot which nestled in the corner of Almunia's net.
The Gunners might have restored their lead when Emmanuel Eboue's mis-hit shot from the edge of the area inadvertently became a perfect pass for Bendtner, who turned and drove the ball well over the bar.
As the play flowed from end to end in the opening stages, Almunia saved well at his near post from a good Moore effort, while a Gael Clichy cross was punched away by West Brom keeper Carson, but only to Eboue whose shot was wildly off-target
Arshavin had an effort at goal from just outside the area that went wide of the left-hand post, while Moore, looking lively for the Baggies, had a header just over the bar as the home side enjoyed a decent spell of pressure.
But that phase of play was abruptly ended by a second Arsenal goal on 38 minutes. Andrey Arshavin whipped in an inswinging free-kick from the left and captain Kolo Toure ran untracked to meet it at the near post with a glancing header.
Six minutes later - a minute before half-time - the Gunners went further head, and this time Toure was the provider. The Albion defence was caught napping again as the Ivory Coast central defender's ball over the top was taken superbly by Bendtner on his knee and volleyed home emphatically by the oft-maligned Danish striker.
Arsenal came out for the second half having been forced to make a change, Abou Diaby replacing Kolo Toure, who had picked up a calf injury; Almunia took the skipper's armband.
The Gunners quickly picked up the pace again, Bendtner squaring the ball to Arshavin in front of goal, only for the Russian to place his shot too close to keeper Carson, who gathered comfortably. Then the inspired Bendtner rode a succession of tackles before setting up Arshavin again. This time, the ex-Zenit playmaker showed great control to shift the ball instantly from left foot to right before shooting, but Carson saved well.
Bendtner it was again who collected the ball on the right and cut in to shoot, his low effort thudding against the far post as he sought a hat-trick. Arsenal had already the woodwork more times than any other Premier League club this season.
Albion earned some respite with a speedy counter-attack that ended with Marc-Antoine Fortune electing to shoot from an angle when a square-pass to Moore might have yielded greater dividends
Bendtner put another effort over the bar, and Aaron Ramsey - on for Eboue after 67 minutes - forced a save from Carson as the game drew to a close.
The Gunners had failed to score in he second 45 minutes, but three before the break ensured a much-needed victory. How significant it will prove to be in their bid to overtake Villa will become clearer after Villa's game at Manchester City tomorrow. But for the moment they are a more manageable hree points behind Martin O'Neill's team.
As for West Brom, hey are now staring relegation in the face after this sixth straight winless encounter.
West Brom: Carson, Zuiverloon, Meite, Donk, Robinson, Morrison, Greening, Koren, Brunt, Moore, Fortune. Subs: Kiely, Hoefkens, Cech, Kim, Filipe Teixeira, Menseguez, Borja Valero.
Arsenal: Almunia, Sagna, Toure, Eboue, Clichy, Song Billong, Djourou, Nasri, Denilson, Bendtner, Arshavin. Subs: Fabianski, Diaby, Van Persie, Vela, Ramsey, Gibbs, Merida.