Georgios Samaras scored twice in the second half Sunday to give Celtic a 2-0 win at Rangers and a four-point lead over its fierce Glasgow rival at the top of the Scottish Premier League.
Celtic had lost its last three visits to Rangers but Samaras put his team ahead in the 62nd and completed the win eight minutes later with a penalty he earned.
For his first league goal of the season, Samaras beat goalkeeper Allan McGregor to a pass through the defense, knocked it past his opponent and rolled it into the net from an angle. The second was a penalty just inside the post that he won when Madjid Bougherra tripped him on the edge of the area.
Celtic has 45 points to Rangers' 41, but the defending champions have played two games fewer.
"Samaras was the big difference today, when he plays like that he is virtually unplayable," Celtic manager Neil Lennon said. "Once we weathered the initial flurry I thought we were by far the better side."
St. Johnstone beat Inverness 1-0 in Sunday's other game, a day after Hearts maintained their slim hopes of winning a first title since 1960 with a 1-0 win over Edinburgh rival Hibernian.
Third-place Hearts moved to within two points of Rangers after Kevin Kyle headed in Arvydas Novikovas' 86th-minute cross to score for a fourth straight match.
