Seventeen-year-old Thomas Reilly's stoppage-time equaliser for St Mirren prevented Motherwell going top of the Scottish Premier League.
Michael Higdon had continued his habit of scoring in Motherwell versus St Mirren encounters at Fir Park to fire the home side ahead after two minutes.
But St Mirren took control after the break and Well's Shaun Hutchinson was red carded for the second game running.
Well paid for that when sub Reilly fired late on for a deserved point.
Three points would have put Motherwell a point ahead of Celtic in the SPL, but they instead lie a point behind the reigning champions, who also have a game in hand.
Well handed first starts to 19-year-olds Steven Hetherington and Fraser Kerr with Chris Humphrey on the bench after picking up a knock in the 2-0 defeat to Levante on Thursday evening and Tom Hateley missing out for the first time in 143 games.
Stuart McCall's side quickly overcame their Europa League blues with a goal after just over a minute gone.
A ball played through skidded fairly high on the greasy surface, it was mis-read by Lee Mair and Higdon took a touch and slotted it beyond Craig Samson.
The striker has now scored in the last three meetings between the sides at Fir Park, the first of those as a Buddies player.
St Mirren, often criticised for being too deliberate in their passing football, recovered from that early blow and were looking to move the ball quicker upfield.
Buddies boss Danny Lennon had made one change from the side that fell to a 2-1 defeat by Hibernian, David Van Zanten coming into the defence for long-term injury victim Darren McGregor.
However, St Mirren were steady at the back and a threat going forward and only an excellent stop by goalkeeper Darren Randolph prevented the influential Paul McGowan from levelling the scoring after a neat through ball from Graham Carey on 17 minutes.
Sam Parkin also headed wide of the target, while Well's Henrik Ojamaa flashed an effort just wide.
Steven Thompson passed up a good opportunity to level the game six minutes before the break - losing his footing as he prepared to have an effort on goal.
Higdon had a chance to extend the lead but could only produce a weak effort directly at Samson, but it was all St Mirren after the break.
Kenny McLean and Carey tested Randolph, while Well's Jamie Murphy and Higdon blazed efforts high over the bar.
Hutchinson received a yellow card for dissent with 10 minutes remaining and seven minutes later was shown another after he lunged in on Reilly.
Carey stung the palms of Randolph from distance before Reilly bundled in the equaliser after Randolph did brilliantly to deny Thompson.
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