The latter sealed the points in the 75th minute and substitute Tony Watt added a fourth with the last kick of the ball.

The win extended Motherwell's lead in third spot in the Ladbrokes Premiership to three points following Aberdeen's draw at Kilmarnock.

Fontaine broke from a pack of players and got away from Peter Hartley to convert Iain Vigurs' corner as County looked to make it three consecutive Fir Park wins.

Campbell had a near-post header saved as Motherwell tried to respond but Mark Gillespie had to push away Billy McKay's deflected strike to prevent the hosts going further behind.

Hartley was involved as Motherwell equalised in the 17th minute. The defender headed Liam Polworth's deep cross back into the six-yard box and O'Hara lashed home the bouncing ball.

County were looking vulnerable and goalkeeper Ross Laidlaw raced off his line to block from Jermaine Hylton following Polworth's defence-splitting pass.

The home fans were paying tribute to fellow supporter Mark Paton, who died last week aged 24, when their team went in front.

Declan Gallagher's ball set Liam Grimshaw down the right and his cross was volleyed off the bar by Hylton. The rebound fell for Campbell, who found the top corner from 12 yards.

Christopher Long's pace was causing County problems and the striker skipped past Callum Morris early in the second half but had a shot blocked from a tight angle with two team-mates free in the six-yard box.

Laidlaw soon made a brilliant save to push Long's six-yard strike on to the post.

Motherwell remained on top and were showing signs of their confidence returning but needed a third to settle the home fans' nerves given their recent run, which included losing late winners against St Mirren and St Johnstone.

The clincher was provided by Long, who was back in the team after his recent red card against Hamilton. The forward beat Marcus Fraser and drove the ball across for Campbell to tap home from six yards.

With a trip to face in-form Hearts coming on Saturday, Stephen Robinson left David Turnbull on the bench following his first appearance since summer knee surgery last week.

Watt provided a classy finish to claim his first Motherwell goal after being played through by Campbell in stoppage-time.