The fight for the Clydesdale Bank Premier League title will go right to the last match after Rangers beat St Mirren 3-0.
A Kris Boyd strike and two from Jean-Claude Darcheville gave the Gers vital points - and goals.
It means Rangers and Celtic have equal points, but defending champs Celtic now have a four goal advantage.
Who wins now depends on Rangers' trip to Aberdeen and Celtic's clash with Dundee United at Tannadice on Thursday.
This was Rangers' first away win in the league since the 4-0 thrashing of Hearts back in February.