Celtic opened up a 13-point lead at the top of the Scottish Premier League yesterday but they were made to sweat for their 2-0 victory over second-from-bottom Motherwell at Parkhead.

The game seemed to be heading for a scoreless draw when Celtic manager Martin O'Neill threw on winger Bobby Petta for defender Bobo Balde in the 77th minute - and his boldness paid off with the opener within four minutes.

John Hartson knocked Paul Lambert's long-ball into the path of Henrik Larsson, who shrugged off the challenge of Eric Deloumeaux before shooting past goalkeeper Stephen Woods.

Hartson sealed victory in injury time when he fired Larsson's centre home from close range for his 13th goal in as many starts.

Celtic, who lost their only league game of the season against Aberdeen on December 22, have 61 points from 22 games, 13 points more than Rangers whose game at Kilmarnock was called off due to a frozen pitch.

After the game, O'Neill said: "We know that if we win 12 out of 16 games then we have won the championship - this was a massive win for us."

Livingston, who thrashed Aberdeen 6-1 in the league Cup earlier this season, handed out another thumping to the same opponents. Second-half goals by Steve Tosh, Philippe Brinquin and Marvin Andrews gave them a 3-0 victory at Pittodrie as the promoted side consolidated their third-placed position.

Livingston have 40 points from 22 games, seven more than fourth-placed Aberdeen.

Elsewhere, James Paterson struck three minutes from time to give Dundee United a 1-0 victory at Hibernian. The visitors also had Jamie Fullarton sent off.

And a goal in each half by Gary Wales and Ricardo Fuller gave Hearts a 2-0 victory at bottom club St Johnstone.

The Dundee-Dunfermline clash was also postponed due to the weather.