Scottish Premier League leaders Rangers fell to a 2-1 defeat away to St Mirren on Christmas Eve.
Lee Wallace gave the Gers an early lead but the visitors then had Lee McCulloch dismissed, before goals from Aaron Mooy and Paul McGowan allowed St Mirren to take over prior to the break.
With time running out, a poor day for Rangers was compounded when Dorin Goain received his second booking and was shown a red card, as Celtic closed the gap at the top of the SPL to a point with victory over Motherwell ahead of Wednesday's Old Firm clash.
Rangers started well, with Kyle Lafferty missing an early chance, and took the lead after just 11 minutes. Sasa Papac provided a superb and incisive pass from the left-back position for Wallace, who forced his past Marc McAusland before poking the ball beyond Craig Samson.
Midway through the period, Gregg Wylde’s free-kick beat Samson, but an incident in the box had been spotted by referee Steven McLean. A few seconds later, Rangers were reduced to 10 men, with McCulloch adjudged to have elbowed Graham Carey, although the contact was not particularly powerful.
The hosts immediately took control and in the lead up to the break, scored twice to turn the game on its head. Firstly, Mooy evaded several challenges and riffled home a fine drive from 15 yards, before David van Zanten’s simple pass allowed McGowan to beat Allan McGregor with the outside of his right boot.
Marc McAusland went close for St Mirren early in the second half but Nikica Jelavic then shot wide from eight yards for Rangers at the other end, as the visitors took over.
However, the Gers could not find a leveller and their chances of doing so more or less ended when Goain was sent off with three minutes of normal time remaining.
McGowan, who had rounded McGregor, was denied his second late on as Papac got back to clear off the line, but the job had already been done by the hosts.