Rapid doubles from Lionel Ainsworth and John Sutton secured Motherwell’s first derby win of the season after three previous defeats against the Accies, and it moves them four points clear of the foot of the table.
Accies had started brightly and Ali Crawford burst forward from the centre circle to run through the middle of the Motherwell defence before hitting a weak shot straight at George Long from 20 yards with 90 seconds on the clock.
Crawford was involved again when he pounced on a loose ball to set up Grant Gilespie but the Accies midfielder sent a rising drive over the target from the edge of the box with just Long to beat.
At the other end Scott McDonald was played in at the left side of the Hamilton penalty area and he thundered the ball across the face of goal but there were no talkers.
The visitors survived a bigger scare four minutes later when Ainsworth got in behind the Accies defence and burst into the box, but his low drive was too close to Michael McGovern and the goalkeeper got down to save.
Ainsworth then laid the ball into the box for Erwin, whose shot was blocked by a defender before he knocked the rebound behind for a goal kick.
But Motherwell’s confidence was growing, and Accies defender Garcia Tena took the ball off the toe of the onrushing Erwin at the back post from a low McDonald delivery, with the goal gaping.
Hamilton responded quickly when Crawford found space on the right flack and chipped the ball back to the front of the penalty area where Dougie Imrie arrived to volley the ball against the post with the outside of his foot from 22 yards.
A minute before the break Jason Scotland weaved into the box and as Josh Law intercepted he sent the ball past the diving long and inches wide of his own goal.
The first goal eventually arrived on 49 minutes when Keith Lasley rolled a quick free-kick to Ainsworth and he took one touch before hammering the ball into the corner of the net from 25 yards.
Motherwell doubled their lead a minute later as Marvin Johnson created some space on the left flank and delivered the ball across the six-yard box which just eluded Lee Erwin, but Ainsworth arrived behind the striker and fired home from a tight angle.
Hamilton were stunned by Ainsworth’s quick brace and their situation deteriorated further when they were reduced to 10 men after Johnson slid in to win the ball from Imrie and as he got on to his feet to sidestep Darren Lyon (65), the Accies midfielder went through him with a reckless lunge.
Accies substitute Nigel Hasselbaink almost made an instant impact when worked a one-two with Kieran MacDonald and stabbed the ball wide at the front post with 20 minutes reaming.
McGovern had prevented Ainsworth from grabbing a treble when the keeper clawed away a dipping half-volley from McDonald’s cross.
And Ainsworth was inches away from his hat-trick again when McDonald released him with a weighted pass and he crashed a low shot just wide of the far post three minutes later.
Ainsworth turned provider on 80 minutes when a low Erwin cross found him at the far side of the box and the winger returned the ball to the back stick for Sutton to nod over the line shortly after the big striker came off the bench.