Falkirk fell to defeat in their first competitive game of the 2018-19 season as Montrose left The Falkirk Stadium with a 1-0 victory.
Martin Rennie scored what turned out to be the winner on 19 minutes when he raced in behind the Falkirk defence to hammer home.
The visitors looked comfortable for large stages, but had to hold on at times too as they secured their three points. The Bairns were disappointing and were booed off by a section of the home support after the defeat.
After an even opening quarter of an hour, Falkirk had a big double chance. Dylan Mackin's original shot was parried by Montrose goalkeeper Allan Fleming, and Dennon Lewis' follow up smashed the crossbar from all of 25 yards.
Five minutes later, though, the visitors took the lead. Craig Johnston's long lofted through ball was perfect for striker Martin Rennie, and he took the ball down before blasting past Leo Fasan from close range.
Deimantas Petravicius had Falkirk's next opportunity just after the half hour, but his low drive was denied by Montrose keeper Allan Fleming.
Fleming was picking the ball out of his net on 42 minutes, but was saved by the linesman's flag. Dennon Lewis' lobbed effort looped over the keeper but he was clearly in an offside position.
Lewis was nearly in two minutes later after a misjudgement from Sean Dillon. The striker found himself in behind but keeper Fleming was again alert to deny him.
Into the second half and Montrose had the first chance. Substitute Danny Cavanagh curled just wide from 30 yards, tricking the visiting supporters into celebrating.
Just a minute later and another goal ruled out for the Bairns. This time Deimantas Petravicius nodded in from close range only to see the flag up, and this time it was a much tighter call.
Closing in on the hour mark, Dennon Lewis had his third chance of the afternoon. Petravicius got to the byline but Lewis could only turn his low cross into the side netting.
With Allan Fleming having a great game at one end, Leo Fasan had to be very quick to react to Ryan Ferguson's goal bound effort at the other. The Italian got a superb fingertip to the ball to turn it behind for a corner.
Into a frantic last 15 minutes and Kevin O'Hara had two huge chances. The 19-year-old was denied at close range after a fine cross from Dan Turner, moments before he was once again denied by a combination of defender and keeper.
The Bairns fans let their frustrations be known with three minutes left as Kevin O'Hara massively overhit a cross from a two on one situation and the visitors held on for a well-earned three points.
Falkirk sit bottom of Group B after one match, with Forfar Athletic visitors to The Falkirk Stadium on Tuesday evening.