Falkirk 0 Clyde 1: Ray McKinnon's men caught cold by late Darren Smith strike
Falkirk missed the chance to go top of the league, and fell further behind the top two after being caught cold by Clyde.
The Bully Wee gave the Bairns their second league defeat of the season, after inflicting the first back in August.
And they were worthy winners against the Bairns with a performance that belied their sixth placed status in the league table.
An end-to-end first half, where the Bully Wee had the better of the chances, ended scoreless but as Falkirk pressed for a winner to no avail, they were picked off at the back late on by a howitzer from substitute Darren Smith that beat Cammy Bell from 25-yards and flew in off the underside of the bar.
The threats had been there prior, Clyde had a goal ruled out for offside but so too did Falkirk when Conor Sammon knocked in Gregor Buchanan's header at close range, but too many chances went a-begging for the Bairns against a spritely opposition.
Chris Johnston gave the home side a torrid time in the first half and were it not for despairing dives from Michael Doyle and Cammy Bell to deny the little winger, his opposite wide man Ally Love and a great stop by Bell to deny David Goodwillie, the Bairns would have been behind.
And they were slow to start. Conor Sammon had more time and space than he realised just six minutes in when a Paul Dixon pass fell to him ten yards from goal, but David Mitchell gathered.
The striker was booked for a later altercation with the goalkeeper when David McMillan was involved in what appeared a sickening collision but he was able to proceed, but he couldn't score. Even stretching to prod a Louis Longridge deflected striker it was all gathered up by Mitchell, playing at his former home and with a point to prove at his old employers.
It was an end-to-end first half but Falkirk should have had a penalty when Declan McManus was manhandled inside the area by Craig Howie but ref Mike Roncone was not interested. Likewise he wouldn't give a free-kick right on the edge of the area when an off-colour Charlie Telfer was barged over.
But they were far from pivotal and a long way from the causes of the Bairns' defeat.
An attacking line-up with Louis Longridge and Declan McManus flanking McMillan and Sammon should expect goals, but with the back four pre-occupied by the Bully Wee's three-pronged and very capable attack, the midfield failed to get a grip on the game.
In the second half it was a similar story, though Falkirk found joy up the right with Michael Doyle's over-lapping runs and chasing back in a worthy man-of-the-match performance.
But Clyde sat in tighter than they had in the first half and caught the bairns on the break, incisively time and again.
Morgaro Gomis had no option but to take a booking for a foul on Michael Lamont in full flight and from the resultant free kick Martin McNiff converted at close range - only to see the effort ruled offside.
Likewise at the other end Gregor Buchanan saw a net-bound header given added insurance by Conor Sammon close in but the Irish intervention ruled the effort out for the same infringement.
The Bairns had been let-off but they wouldn't be given another pass with Smith's finish with aplomb. Ray McKinnon made one change bringing Aidan COnnolly on for Longridge - but prompted the ire of the south stand for the substitution.
His players couldn't get them back on side either as Declan McManus should have done much better when close in on the on-rushing Mitchell but pulled his shot wide, and Mitchell also denied a Doyle drive from 25yards with a great two-handed stop that gave the Bully Wee the impetus.
Then Smith thundered a shot off the underside of the bar to land the decisive blow Clyde had been threatening and to make matters worse Gomis saw his second yellow, and a resultant red as Falkirk pushed for an equaliser to keep pace with Raith Rovers and East Fife above them. It didn't come, and Gomis walked with three minutes to play and one final chance for Falkirk when Sammon's knockdown to Buchanan was fired over awkwardly by the captain.
The Bairns got what they were looking for in Kirkcaldy with Raith and East Fife drawing, but they couldn't take advanatge and slipped one point further off the summit.