West Brom put their Championship promotion challenge firmly back on track after a fine second-half performance crushed in-form Plymouth at the Hawthorns.

The visitors looked bright in the opening period but once substitute Zoltan Gera had broken the deadlock in first-half stoppage time, Albion stepped up a level.

A fluke from Ishmael Miller extinguished any hopes of a comeback before Roman Bednar hit a third to ensure a first league win in a month which closes the gap on the leaders.

Miller returned to Tony Mowbray's side as top scorer Kevin Phillips was ruled out with a knee injury but the understudy curled the clearest opportunity of the first half wide before Gera struck.

Paul Sturrock's visitors could have gone level on points with their hosts with a fifth successive league win and looked bright without calling Dean Kiely into action in the opening 45 minutes before struggling to contain a much-improved Albion after the break.

Filipe Teixeira was forced off through injury after just 18 minutes following a challenge from Gary Sawyer, with Mowbray bringing on Gera in his place.

Miller should have opened the scoring moments later when he latched on to a Roman Bednar flick, cut inside past the challenge of Krisztian Timar but curled his left-footed shot wide from the edge of the area.

Gera looked in determined mood to show he should have been in the starting XI and twice had the Hawthorns crowd on their feet with marauding runs down the right.

Argyle were dealing well with the threat as Albion looked to be missing the clever link-up of Phillips but then, in first-half stoppage-time, Bednar latched on to an awful header from Russell Anderson before rounding goalkeeper Luke McCormick.

He pulled the ball back for Miller, and while the recovering keeper did well to save his shot, Gera nipped in to score.

Miller then went close to doubling the lead in the opening seconds of the second half but, after shaking off Anderson, saw his shot deflect off Paul Connolly and loop onto the roof of the net.

And the profligate Miller then wasted a glorious chance just before the hour mark.

Paul Robinson cut out a slack pass from Argyle midfielder Nadjim Abdou and slid Miller in with a great early ball.

The burly striker again shrugged off Anderson but attempted to round McCormick when he should have shot and got the ball caught under his feet.

It was a poor finish from Miller but incredibly, just seconds later, he did score in bizarre fashion.

A long 59th-minute free-kick found the striker on the edge of the area with his back to goal.

He appeared to be falling backwards under pressure but somehow flicked the ball over his head and it sailed over McCormick and into the far corner.

Miller looked as bemused as anyone to find the net before being replaced by on-loan Aston Villa forward Luke Moore.

And Albion put the result beyond any doubt in the 67th minute with a killer third.

Jonathan Greening's left-wing cross to the far post was headed back into the six-yard box by Gera and Bednar swept the ball in from close range with the aid of a deflection.

The hosts were suddenly in rampant mood. A sweeping crossfield ball from Moore put Gera in and he was only denied a fourth by a fine block by the flying Sawyer.

Chris Brunt typified the growing confidence by trying his luck from fully 35 yards and his piledriver flew inches wide.

Robert Koren then danced through a tired looking Argyle defence but curled his shot narrowly wide from 15 yards.