The women’s 100-meter breaststroke is no stranger to history-making moments.

Four years ago, it was Lilly King and Yulia Efimova finger-wagging at one another as they dueled in the pool.

On Monday night, it was Lydia Jacoby — 17 years old and the first Alaskan Olympian in swimming — who made history by taking down both King and South Africa’s Tatjana Schoenmaker in a time of 1:04.95 to win gold. It was an upset few saw coming.

Jacoby overcame both swimmers in the final 15 meters, showcasing just how good she is in the back half of the race. King, the world-record holder, settled for bronze.

The only swimmer to break 1:05 in the heat, Jacoby now sits seventh all-time on the performance list.

It’s an incredible feat for the Alaskan, who trains in short course yards because Alaska has one 50-meter pool in the entire state. Now, not only is she the first Alaskan Olympian in swimming, but she’s also the first Alaskan ever to win a gold medal in swimming. The reactions back home matched the accomplishment.

The swim also lands Jacoby on another elite-level list: In the past 20 years, only Katie Ledecky and Missy Franklin were younger when they won individual gold medals.