Simon Cox’s eighth goal of the season ensured Roberto Di Matteo’s team-change gamble paid off for 10-man Albion at Home Park.

The Baggies head coach made four changes from the side that had started the last five matches and stayed unbeaten.

Cox – one of the men brought in – struck the only goal of a bad-tempered game on 66 minutes to keep his side in the Championship’s top two.

A rare penalty miss from Graham Dorrans with seven minutes remaining ensured a nervous ending for the visitors, but they held firm despite losing Jerome Thomas in stoppage time to a red card for a foul on David McNamee.

Abdoulaye Meite and Gabriel Tamas also performed well at the heart of defence, after Di Matteo sprang a surprise by resting Jonas Olsson.

One change was enforced for Albion with Joe Mattock replacing the injured Marek Cech but there were three more with Meite, Cox and Gianni Zuiverloon in for Olsson, Gonzalo Jara and Robert Koren.

The Baggies held a slight first-half edge, but both sides found the going tough on the horrid surface.

Albion defender Tamas had to make a crucial interception to block a sixth-minute effort from Alan Judge and then headed wide at the other end from a Graham Dorrans corner.

But the game lacked spark until the final 15 minutes of the half, when both sides began to look more threatening.

Dorrans found himself in a shooting position on the edge of the Plymouth box, but fired too close to goalkeeper David Stockdale.

The visitors had the best chance of the half on 36 minutes when Cox released Roman Bednar, who skipped past Gary Sawyer into the box but was denied by a smart low save from Stockdale.

Tamas came to Albion’s rescue again a minute later when Jamie Mackie ran behind Meite but was tackled well by the defender, as Plymouth’s penalty appeals were waved away by referee Steve Tanner.

The second-half almost began in the perfect fashion for Albion, as Cox got the better of McNamee on the left flank and fired in a cross but Roman Bednar could not turn it in.

Dorrans and Mackie both fired wide for their respective teams before a tackle by Mattock caused a flare-up that livened up the action.

The full-back lunged in on Damien Johnson, McNamee retaliated and all 22 players became involved in a shoving match but Mattock escaped with a yellow card.

Mackie had a shot blocked by Chris Brunt moments, before Albion struck their decisive blow.

Thomas collected a pass wide on the right, Bednar competed with Sawyer at the far post for his inswinging cross and the ball sat up for Cox to lash home an emphatic half-volley.

Albion were then awarded a spot-kick late on when substitute Luke Moore was tripped just inside the box by McNamee, but Dorrans put his effort too close to Stockdale and the goalkeeper saved.

Thomas received his marching orders in stoppage time after lunging at McNamee and the referee reached straight for his red card.

The challenge, close to the touchline, sparked another melee with substitutes and coaching staff involved.