Motherwell 1 Hamilton 3
Motherwell defender Peter Hartley endured a day to forget as Hamilton came from behind to win 3-1 at Fir Park.
The hosts were leading through Craig Tanner's third-minute goal when Hartley was penalised for handball to allow Dougie Imrie to level from the spot four minutes before half-time.
The centre-back's sliced clearance then allowed Rakish Bingham to score and Greg Docherty sealed Hamilton's first victory over their Lanarkshire rivals in eight matches.
Hartley was then involved in a post-match melee as he barged into Imrie as the Accies player and Motherwell goalkeeper Trevor Carson squared up. He left the field before any action was taken but he could now face a suspension after being booked during the penalty incident.
It was an eighth game without victory for Motherwell, who are now one point ahead of Accies in eighth place in the Ladbrokes Premiership.
There was an emotional precursor to the derby when Louis Moult said his farewells on the pitch before there was a minute of applause for Phil O'Donnell a day after the 10th anniversary of his death in Motherwell colours.
Stephen Robinson had warned his strikers to step up ahead of Moult's move to Preston and the Well boss handed George Newell his first start and got the perfect response early on.
Ryan Bowman had already forced a double save from Gary Woods before crossing for Tanner to steer the ball high into the net at the near post.
Tanner hit the side net after a similar move as Motherwell dominated early on but Hamilton came back into it and both David Templeton and Massimo Donati threatened.
The hosts got on top again and Gael Bigirimana had a penalty claim rejected when his powerful strike was blocked, before Accies were awarded a penalty from a similar incident.
Hartley threw his body in the way of Ali Crawford's volley and the ball struck the top of his arm, prompting Andrew Dallas to point to the spot. Imrie stroked the ball just inside a post.
The home side lost Allan Campbell to injury before the break and Hartley suffered more agony eight minutes after the restart when his sliced clearance fell invitingly for Bingham. The striker had a long way to run but nobody could catch him and he slid the ball underneath Carson.
Robinson brought on Alex Fisher and moved three up front. Woods punched clear from Bigirimana as Motherwell pressed but Hartley must have known it was not his day when Dallas ignored his penalty claim when he went to ground following a tangle with Xavier Tomas.
Accies went further ahead with 13 minutes left when Docherty sprinted outside two players and fired into the far corner.
There was no way back for Motherwell and the only time the home fans got off their seats in the closing stages was when Imrie smashed a clearance into their midst for the second season running after being the subject of abuse throughout the game.
The drama continued after the final whistle as Imrie had an exchange with the home support before the flashpoint with Carson and Hartley.