Four goals - including a virtuoso strike from James McFadden - plus two red cards and a torrent of bookings further spiced up a game that always promised to be an explosive one following a summer of bad blood between the clubs.
Despite playing most of the second half with only ten men, Motherwell were twice ahead with both goals coming from McFadden but the visitors hit back to claim their third successive draw at Fir Park.
Thistle actually dominated early on with Stuart Taylor heading over from close range after clever play from Gerry Britton and David Rowson. Moments later, a goalbound drive from Ricky Waddell was blocked by the shin of defender Martyn Corrigan.
McFadden had provided Motherwell's only meaningful attack with a searching pass which Grant Murray intercepted at full stretch but the Scotland midfielder's next contribution saw him blast his team ahead after nine minutes.
McFadden first slipped past the challenge of Ian Ross before finding the top corner of the net with a curling left footed effort from 20 yards.
Fine individual skill also gave Partick their well-deserved equaliser in the 26th minute when striker James Grady danced along the left touch line and clipped in a perfect cross which Britton nodded past goalkeeper Gordon Marshall.
Thistle inexplicably stopped playing at that time and Motherwell's best spell of the match was rounded off by driving runs from Corrigan and Stephen Pearson, only for Alex Burns to spoil things by straying offside.
Pearson's dismissal just three minutes into the second half for elbowing David Lilley ought to have handicapped the home team yet they continued to hold the upper hand.
A free-kick from Derek Adams missed McFadden's forehead by inches while Keith Lasley and Adams himself both wasted decent opportunities.
McFadden's low improvised finish after 69 minutes looked enough to give the ten men a famous victory but with eight minutes remaining Partick substitute Jamie Mitchell reached the byline on the left and floated over a tempting ball which Stuart Taylor headed high past Marshall.
Thistle's Murray was then sent off for his second bookable offence.