Steve Bruce piled on the pressure at his former club Birmingham City to the KC Stadium as Hull City strengthened their promotion credentials.
On-loan George Boyd made his full début for the Tigers, replacing Corry Evans in midfield.
À fourth successive Championship win at the KC Stadium would be enough to tale Hull back into the top two.
It took Peterborough’s Boyd less than minute to make an impact, racing onto Robbie Brady’s ball down the left channel and sidestepping goalkeeper Jack Butland before sidefooting home the opener.
It was soon 2-0, Gedo chasing na clearance from midfield and outmuscling Steven Caldwell before calmly slotting the ball home.
The rampant Tigers would have been 3-0 ahead had not Butland made a great double save from Boyd and Gedo after Brady crossed to the near post.
It did become three in the 33rd minute when Boyd saw his initial shot blocked by a defender but reacted to hit the rebound home despite Butland getting a hand to it.
Birmingham recovery hopes were extinguished five minutes after the break when Robert Koren fired home Hull’s fourth from outside the area.
Butland, who had got a hand to Koren’s drive, then produced a wonder save to deny Boyd his hat-trick from a downward header.
The Tigers went nap in the 76th minute as a brave header from Gedo converted a fierce cross-shot from Boyd which was going wide.
Peter Lovenkrands made it 5-1 with a shot from outside the area seconds after Boyd had departed to a standing ovation.
Chris Burke got his reward by making it 5-2 after being teed up by Nikola Zigic but it could not stop Hull going two points clear of Watford into second place.
For full match report and reaction, read Sports Monday, free in Monday’s Yorkshire Post newspaper.