What was supposed to be a picture-perfect race day on Toronto’s waterfront turned into an unforgettable marathon mix-up.

During Sunday’s Toronto Waterfront Marathon, disaster struck when several elite women runners accidentally followed the half-marathon route to the finish line — 22 kilometres too early.

The confusion happened around the 20 km mark, where the course splits: half-marathoners head straight down Bay Street to finish near Nathan Phillips Square, while full marathoners turn right on Wellington for another long stretch before looping back downtown.

Leading Ethiopian runner Shure Demise — a two-time Toronto champion — made the correct turn and stayed on course. But for Gojjam Enyew and Dibabe Beyene, both also from Ethiopia, the mistake proved costly. Enyew even broke the tape at the half-marathon finish, her face turning from triumph to heartbreak as she realized the error.

Another elite, Nigsti Haftu, tried to retrace her steps to rejoin the marathon but had already fallen too far behind.

Race organizers confirmed that athletes had been briefed during Saturday’s technical meeting about the split, but in the heat of competition — with fatigue, focus, and adrenaline all colliding — it’s easy to see how chaos unfolded.

Demise continued on pace, crossing the halfway mark in 1:10:04, on track for a 2:25 finish — just a few minutes shy of the course record (2:22:16).

Meanwhile, Ben Flanagan and Rachel Hannah were leading the Canadian contenders for national titles, while Salome Nyirarukundo (Rwanda) and Dayna Pidhoresky (Canada) dropped out earlier in the race.

It was a tough lesson on how even the world’s best athletes can take a wrong turn — literally. In marathons, one split-second decision can rewrite the story.