An entertaining first half at St James Park on Saturday was dominated by Peterborough, who looked dangerous every time they went forward and Exeter defender Troy Archibald-Henville broke the deadlock when he stooped to head Nathaniel Mendez-Laing's cross past Paul Jones and into his own net.
Exeter equalised nine minutes into the second half when John O'Flynn slipped in Nardiello and his shot rattled off the underside of the crossbar before crossing the line.
The Grecians went in front when Liam Sercombe's cross found Jamie Cureton and he took one touch before ramming the ball into the corner.
But their hopes of a victory were denied by Lee Tomlin, who came off the bench to send a low shot into the bottom corner from 20 yards for a deserved share of the spoils.
Both teams had chances to win it late on with Seth Nana Ofori-Twumasi's shot deflecting just over for the Posh, while Archibald-Henville saw his header hacked off the line.