American swimmer Bobby Finke had a stunning come-from-behind victory that shocked even his teammate

The American swimmer Bobby Finke stormed from behind in the final 50 meters of the men's 800-meter freestyle on Wednesday night to take an unlikely gold medal.

Finke, 21, spent most of the race trailing Italy's Gregorio Paltrinieri, who jumped out to an early lead.

But as the race closed through the final 50 meters, Finke hit the afterburners, turning in a stunning split of 26.39 seconds before touching the wall first.

In the final seconds of a race that had pushed athletes to the brink for 800 meters, Finke was moving like a sprint racer.

Looking at how far back Finke was at the final turn, his comeback looks only more improbable. Somehow, he was able to claw the leaders back in the pool to take gold.

Watching from the practice pool, Finke's teammate Caeleb Dressel, a fellow Florida Gators swimmer, looked on in awe.

Dressel surely has a lot of faith in his teammate, but even he couldn't hold back his shock at the result.

Finke is scheduled to race again in the men's 1500-meter.