Greig Spence scored the only goal of the game five minutes from time as Raith deservedly reached the semi-finals of the Ramsdens Cup at the expense of Falkirk.
Rovers dominated their Championship rivals but the game appeared to be heading for extra-time due to some wasteful finishing before Spence popped up with the winner.
Falkirk made a bright start and Rory Loy missed a couple of chances to put them in front but Raith started to get into their stride, with striker Calum Elliot and midfielder Grant Anderson missing chances to open the scoring.
Elliot passed up another opportunity seven minutes before the break when he headed over the crossbar and Liam Fox was wasteful with chances either side of half-time.
On-loan Falkirk midfielder Rakish Bingham could have made them pay but he fired wide 15 minutes from time.
But Spence made no mistake at the other end with time running out when he finished clinically with his right foot after collecting Jason Thomson's pass.