Peterborough hammered 10-man Tranmere to continue their strong start to the League One season.
Tommy Rowe fired into the top corner and Tyrone Barnett slotted in before Andrai Jones was sent off for a foul on Barnett in the area and Grant McCann scored the resulting penalty.
Britt Assombalonga scored his fourth of the season with a close-range finish from Danny Kearns' free-kick.
Sub Mark Little completed the rout when he powered home.
The result leaves Ronnie Moore's Rovers with just one point from four league games.
In contrast to their opponents' fortunes the Posh sit joint top with 12 points and have now scored 17 games in their first five matches in all competitions.