Ryan rattled home a cracking 20-yarder, his third stunner of the season on the stroke of half time and Paul Green wrapped up the points with another super strike in stoppage time.
It was cruel luck on Port Vale who battled all the way before crashing to their fourth defeat in the last five games. Vale had much the better of the first half but lacked a cutting edge to their approach play and chances when begging.
The match was spoiled by the blustering conditions but Vale adapted better and should have been in front of themselves and the interval.
Ryan Brown was foiled by a fine save from Stuart Jones in the 19th minute and Micky Cummins missed a good chance when he fired over the top over from close range a minute later.
Billy Paynter was also wasteful when well placed in the 31st minute after Jeff Smith had seen a shot blocked. Vale had cause for regret when Ryan fired Rovers in front against the run of play and it was a different story after the interval as the home side took control.
Simon Johnson hit the bar with a dipping angled shot in the 56th minute and Jonathan Brain did well to save from Jermaine McSporran and Michael McIndoe in quick succession.
Post Vale battled all the way with substitue Chris Birchall forcing a fine save from Jones in the 78th minute. But the home side finished on top and had the last word when Paul Green sealed the issue with a cheeky back heal kick from McSporran's right-wing cross in stoppage time.