Celtic came from behind to win at Fir Park and maintain their late charge for the SPL title.
Chris Porter headed Motherwell in front after an hour, stooping to meet Brian McLean's excellent cross.
But the lead lasted for a mere minute as Scott McDonald nodded in his 30th goal of the season.
Georgios Samaras was then left unmarked at a corner and his header put Celtic eight points clear of Rangers, who have four games in hand.
Celtic swept Motherwell away 4-1 on their last visit to Fir Park three weeks ago but found the home side in more determined mood this time.
The visitors could not find any early rhythm as Mark McGhee's team adopted a high-tempo pressing game.
And, while there was little in the way of goalmouth action in the first half, Motherwell carried more menace in attack.
Motherwell midfielder Keith Lasley was the first to get a sight of goal but his 10th minute shot from 16 yards was deflected wide.
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Celtic full-back Andreas Hinkel tried his luck from distance but failed to test goalkeeper Luke Daniels, who was making his debut for the home side.
Daniels, on loan from West Brom, was then under pressure as Gary Caldwell rose to meet a Shunsuke Nakamura free-kick but the visitors could not capitalise on the keeper's fumble.
On 36 minutes, Motherwell's Darren Smith scampered down the right flank and crossed for Marc Fitzpatrick only for the midfielder to direct his strike straight at goalkeeper Artur Boruc.
Motherwell continued to look the livelier side after the break and grabbed a fine opening goal on the hour when McLean curled in a cross for Porter to head home.
However, Celtic replied immediately with former 'Well striker McDonald nodding in from Nakamura's lofted delivery to the far post.
And Gordon Strachan's team went ahead on 78 minutes when Samaras was left unattended at a Barry Robson corner and the substitute had the simple task of heading in from close range.
The home side, aiming to hold on to third spot, will feel aggrieved since it was a dubious decision to award the decisive corner but poor marking was their undoing for both goals.
Motherwell forced a series of corners in the closing stages but the visitors held firm to claim a vital victory.
Motherwell: Daniels, Brian McLean, Craigan, Reynolds, Hammell, Darren Smith (McCormack 74), Malcolm, Fitzpatrick, Lasley (Murphy 86), Porter, Clarkson (Hughes 81). Subs Not Used: Graeme Smith, Meechan, Lappin, McGarry.
Booked: Malcolm.
Goal: Porter 60.
Celtic: Boruc, Hinkel, Caldwell, Balde, Naylor (Wilson 75), Nakamura (Scott Brown 65), Hartley, Robson, McGeady, McDonald, Vennegoor of Hesselink (Samaras 65). Subs Not Used: Mark Brown, O'Dea, Donati, Hutchinson.
Booked: Robson.
Goals: McDonald 62, Samaras 79.
Att: 9,158
Ref: S Conroy
BBC Sport Player Rater man of the match: Motherwell's Darren Smith 7.15 (on 90 minutes).
Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.
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