Ephron Mason-Clark netted the winner as Peterborough extended their unbeaten run in League One to eight matches with a 1-0 victory at Port Vale.
The only goal of the game came in the 14th minute, when Connor Ripley failed to keep out Mason-Clark’s back-post header from Kwame Poku’s cross.
There were big shouts for a Vale penalty on the half-hour mark, but Ben Garrity was booked for diving having latched onto a short back-pass and gone down under a challenge from goalkeeper Nicholas Bilokapic.
Funso Ojo’s long-range attempt in the 41st minute was well tipped around the post by Bilokapic.
Down at the other end, Ripley produced a superb double save in added time – firstly denying Joel Randall and then Ricky-Jade Jones – to keep the deficit to one going into the break.
Ripley had to be alert again to deny Poku when one-on-one just before the hour mark.
The hosts threatened to equalise in the 67th minute as substitute James Plant’s goal-bound effort was blocked superbly by Ronnie Edwards on the line, but that was as close as they came.