GLASGOW (AFP) - Australia international Scott McDonald scored his first goal in six games as Celtic overpowered Gretna 3-0 on Sunday to cut Rangers's lead at the top of the Scottish Premier League to just three points ahead of next weekend's Old Firm encounter at Ibrox.

McDonald opened the scoring at Almondvale three minutes before half-time when he was first to react to a flick-on from Jan Vennegoor of Hesselink and shot home from close range.

To their credit basement club Gretna, who recently had 10 points deducted for entering administration, did not let in a second goal until the 70th minute when Dutch forward Vennegoor of Hesselink headed in a cross from Aiden McGeady past goalkeeper Greg Fleming.

Celtic substitute Georgios Samaras, on for McDonald, completed the scoring two minutes from time as Gretna suffered their 22nd defeat in 30 league matches so far this season.

The match was played at First Division Livingston's ground after persistent problems with a waterlogged pitch at Motherwell's Fir Park, the temporary base of Gretna, who cannot play league matches at Raydale Park because it does not meet SPL standards.