Tranmere romped to victory against Division Two leaders Plymouth, who were suffering only a second defeat in 13 outings.
The Merseysiders exacted telling revenge for a 6-0 away drubbing earlier in the season.
They built up a two-goal lead by the 22nd minute and were gifted an important third goal seven minutes after half time.
Plymouth on the night were very disappointing. It was hardly a boost for sick manager Paul Sturrock, who did not travel to Merseyside because of a virus.
Assistant Kevin Summerfield took charge but got little response from his side.
Tranmere should have been ahead in the second minute, but David Beresford saw his shot blocked by keeper Luke McCormick.
At the other end, home defender Graham Allen headed off the line from an Ian Stonebridge shot.
Tranmere's opening goal came in the 19th minute from a far-post header by Eugene Dadi from a Mickey Mellon corner.
Iain Hume doubled the advantage on 22 minutes with a close-range effort when set up by Gareth Roberts after good work by Dadi.
It needed a fingertip save by McCormick to deny Mellon in the 28th minute.
At the other end, Stonebridge brought an excellent block from John Achterberg in the 35th minute.
David Norris headed wide for Plymouth on 49 minutes, but all hope went for them three minutes later.
Skipper Graham Coughlan, in trying to dribble out of defence, lost possession to Dadi who advanced forward to net his 12th goal of the season.
Argyle tried hard to get back in the game but enjoyed little luck.
Home substitute Alex Hay had the ball in the net in the 88th minute following a free-kick by Sean Connelly, but offside was given.
It was a disappointing display by the visitors. Tranmere on the other hand turned in probably their best display of the season as they extended their unbeaten run to 11 games.