The £3.8million signing from Nancy, who has largely failed to impress since arriving at Parkhead, replaced Danny Fox and, with almost his first touch, fired a glorious shot past Motherwell goalkeeper John Ruddy.

Georgios Samaras' 14th-minute opener had been cancelled out before the interval by goals from Lukas Jutkiewicz and Mark Reynolds.

Aiden McGeady levelled in the 51st minute and Barry Robson had a penalty saved by Ruddy before Fortune notched the winner.

Kris Boyd scored his second double in as many Clydesdale Bank Premier League games as Rangers cruised to a 3-0 victory against St Johnstone.

The striker twice benefited from slack passing by a makeshift Saints defence in the first half, scoring the opener after only 30 seconds.

Nacho Novo netted on the rebound just after the break as Rangers closed the gap on their Old Firm rivals to two points with a game in hand.

Third-placed Hibernian drew 1-1 at Kilmarnock.

Mark Burchill put the hosts ahead after 54 minutes before Anthony Stokes returned fire six minutes later.

James Wesolowski earned Hamilton a winner 10 minutes from time against Aberdeen, who went down 2-1 at home.

Gary McDonald had levelled Mickael Antoine-Curier's opener before the Australian grabbed the winning goal in the 80th minute.

St Mirren and Falkirk drew 1-1 after Carl Finnigan's 88th-minute strike cancelled out Michael Higdon's opener and Hearts drew 0-0 with Dundee United.