The French keeper won a personal duel with Posh talisman George Boyd to ensure this battle between two high-flying teams ended in deadlock.
Gueret got a hand to Boyd's close-range lob seconds before the interval and Dons skipper Dean Lewington was on hand to hook the Posh ace's follow-up attempt off the line.
The home side were furious not be awarded a penalty by referee Graham Salisbury after Lewington appeared to use his hand.
Dons shot-stopper Gueret was again equal to all that Boyd could produce after the break as well when tipping his goalbound blockbuster over the bar 20 minutes from time.
And Gueret completed a hat-trick of important stops in the dying moments when clawing a wayward header from his own substitute Jude Stirling away from danger.
The two sides had plenty of previous form after both roared to promotion from League Two last season.
Posh also won a thrilling battle at stadium:mk earlier in the current campaign, but this clash failed to hit the heights of past encounters.
That was largely due to the spoiling tactics of the Dons, who were seemingly intent on preventing Posh's flair players from seizing control of proceedings.
The second-placed visitors were rarely seen as an attacking force but the pace of Sam Baldock did provide a headache for the Posh rearguard.
The young wideman twice tested keeper Joe Lewis with speculative efforts from the edge of the area before lone striker Aaron Wilbraham was thwarted by a brave block from Gaby Zakuani.
A point lifts Posh into third place in the League One standings - four points behind their arch-rivals Dons.