A Nacho Novo double helped secure all three points for Rangers against Motherwell at Ibrox and sent the Glasgow side to within one point of Celtic at the top after a comfortable 4-1 victory.
The Spanish striker grabbed a brace before Scott McDonald pulled a goal back for the Fir Park side but strikes from Shota Arveladze and Steven Thompson killed off any hope they had of taking anything from the game.
The win allows Rangers to slash Celtic's lead at the top of the Bank of Scotland Premier League table to a single point again.
Elsewhere, Simon Ford's first goal for Kilmarnock helped earn his team a much-needed 3-1 win over Dundee at Rugby Park.
The English defender netted after 38 minutes to add to Danny Invincibile's 16th-minute opener for Jim Jefferies' side.
John Sutton gave Dundee hope for the second period when he scored just a minute after Ford but Kris Boyd settled the match in the 82nd minute.
Meanwhile, Dunfermline and Livingston were unable to break the deadlock in a dour basement battle. Neither team could carve out a real goalscoring chance in a disappointing game.
Aberdeen gained a point but lost their Bank of Scotland Premier League third place after a goalless draw with tenants Inverness Caledonian Thistle.
Jimmy Calderwood's side slipped down a place after in-form Hibs defeated Dundee United.
The Dons had ample chances to win the game. Richard Foster, Markus Heikkinen, John Stewart and Scott Severin all passed up great opportunities as Aberdeen's lack of cutting edge, which has threatened to undermine them all season, came to the fore.
In the last of today's games, Hibernian racked up their fifth win in six games with a comprehensive 4-1 victory over hapless Dundee United at Tannadice to move into third place.
After going behind to an eighth-minute Jason Scotland goal, the visitors stormed back and efforts by Derek Riordan, Garry O'Connor, Alen Orman and substitute Sam Morrow gave the Edinburgh side an easy victory over a United team.
But Hibs were helped on their way by some poor United defending, which contributed to the home side's downfall.
