Conor Grant drilled against the post for Rovers before Oldham wasted a series of headed chances through Jake Cassidy, Mike Jones and Tim Dieng
Williams missed a clear opportunity when he planted a free header straight at Oldham goalkeeper David Cornell
But the in-form striker pounced again just before half-time as he met Harry Middleton's cross with a miscued volley which spun on to the post and trickled over the line
Oldham replied in the 74th minute when Mark Yeates fired goalwards and Rhys Murphy, who has just returned to the Latics after a loan spell at Crawley, got the final touch from six yards
Murphy could have levelled in stoppage time but he headed over from close range
Source : PA
Source: PA