Trojan condoms might stop sperm in its tracks … but, Trojan students have got some pretty strong swimmers, it seems — ’cause a USC student won the first-ever sperm race.

The much-anticipated battle for L.A. spunk supremacy went down in DTLA Friday night … with Tristan from USC taking on Asher from UCLA — and, we caught the whole darn thing on film, with the event showing just how fast their little swimmers were motoring in real time.

Check it out, the race starts off pretty even — Tristan and Asher’s boys making their way through the channel with ease … until one of Tristan’s swimmers turns into the Usain Bolt of you know what, coming from behind to tear into the lead.

The event also had a celebrity cameo … with Ty Dolla $ign stepping onstage to serenade the crowd, playing his song “Carnival” which also features Kanye West — though he cut the track before reaching KW’s part.

We’ve told you all about the Sperm Race this month … even bringing Tristan and Asher together to chat with us on an episode of “TMZ Live” a few days before the race.

They talked a little trash about who had the best baby-makin’ juice … and, now we have the answer. They also discussed their fitness regimens coming into the big event.

We also spoke with the organizers of the Sperm Race — Eric Zhu and his startup squad — and, they said they wanted to put on a successful event to bring awareness to the dropping rate of fertility in men.