Coco Gauff has smashed her way into her first US Open semifinal.

The 19-year-old Gauff dominated Latvian Jelena Ostapenko, defeating her 6-0, 6-2 in just 68 minutes, the shortest women's singles match of the entire tournament. She's the first American teenager to make the US Open semifinals since Serena Williams in 2001.

Gauff was prepared to go toe-to-toe with Ostapenko and her powerful, decisive style. But playing so hard means Ostapenko lives dangerously on the court. Her shots can go from hugging the line to landing way out of bounds pretty quickly. In the first set against Gauff, every other shot seemed to be a misfire, landing just beyond the line and sometimes way, way beyond.

It was a stunning change from the Ostapenko we saw Sunday defeat defending US Open champion (and world No. 1) Iga Swiatek. In that match, she had 20 total unforced errors over three sets. In the first set against Gauff, Ostapenko had 15 unforced errors, and they cost her dearly.