Billy McKay was the hero for Terry Butcher's side - the striker notching a goal in each half to help Thistle reclaim the league leadership following Celtic's win at Kilmarnock earlier on Saturday.
The game was just 11 minutes old when McKay opened the scoring, Graeme Shinnie's delivery fumbled by Ben Williams and allowing him a routine finish from inside the penalty area.
McKay raced through again moments later only to fire wide and he should have been punished at the other end when Paul Heffernan spurned a glorious chance to equalise.
The visiting defence was proving vulnerable and McKay had already wasted a second-half one-on-one before two goals in the space of two minutes killed Hibs off.
In the 59th minute, more hesitant defending saw Richie Foran tuck home the loose ball - and Hibs barely had time to regather themselves before a neat turn and finish from McKay had sealaed the points for the hosts.
McKay came close to completing his hat-trick with a near post header from Ben Greenhalgh's cross and David Raven struck the bar with a cross-shot late on, but the job was already well done for Inverness.