They dominated for long periods but came up against a resolute Port Vale defence and a five-star display from keeper Mark Goodlad.
The visitors, without a win in their previous four matches, could easily have been three goals behind inside 20 minutes. Goodlad beat out an angled shot by Chris Shuker in the ninth minute and did well to block another effort by the same player on 18 minutes.
Then a minute later he did well to hold a shot from point-blank range by Kevin Ellison.
Vale took the lead on 31 minutes with a first league goal since February for Jeff Smith. He netted with an angled shot from the edge of the box after being set up by Paul Harsley.
The visitors doubled their advantage in first-half injury time. Leon Constantine fired home his eighth of the season from close range after Tranmere failed to clear a Smith free-kick.
Rovers again made much of the running in the second half. Shuker had an effort deflected over in the 48th minute and four minutes later Goodlad did well to turn an Ellison header onto the bar.
Tranmere did pull one back after 57 minutes. Chris Greenacre was left with an easy tap-in after Steve Davies headed on a long Chris McCready ball.
Vale rode their luck late on. Ellison headed inches wide in the 89th minute then in the fourth minute of injury time, Goodlad completed his excellent night's work when making a brilliant stop from the same player.
Shuker was outstanding for the hosts. Goodlad took star billing for Vale, but there was also good displays by skipper George Pilkington, Danny Sonner, Danny Whitaker and Harsley.