Celtic are cruising at the top of the Scottish Premiership and look all set to beat Rangers to the title.
Neil Lennon’s men headed to St Mirren on Wednesday seeking to take another step towards the championship.
And January signing Weah made sure they got off to an excellent start with his fourth goal in a Hoops shirt.
The striker – on loan from PSG – was there to head home a rebound as St Mirren scrambled to clear.
But the ball only just crossed the line after Weah headed it in off the crossbar.
As these images show, the ball did go over the whitewash.
St Mirren goalkeeper Vaclav Hladky did beat the ball away as it bounced back up – but the officials had already spotted that it crossed the line.
Referee Don Robertson waved away protests as St Mirren players complained.
And it could have got even better for Celtic before half time had Olivier Ntcham not squandered a penalty.
Ntcham saw his effort to the keeper’s left saved by Hladky, with Ntcham then blasting the rebound over the bar.