INDIAN WELLS, CA, USA - No.10 seed Jessica Pegula dropped just three games to breeze past Asia Muhammad and move into the second round at the Oracle Challenger Series Indian Wells 125K Event.

A banner day for American tennis saw Claire Liu, Kristie Ahn, Catherine McNally, Francesca Di Lorenzo and Nicole Gibbs all knock out seeded players, while No.2 seed Alison Riske also advanced to join Pegula.

Read more: Bacsinszky topples Mladenovic to advance at Indian Wells 125K

Even more special for the No.10 seed Pegula: with her second-round appearance, the American has officially clinched one of two wildcard spots into the BNP Paribas Open, which kicks off next week.

Pegula had little problems against Muhammad, although she had to edge through in a hard-fought first set featuring eight break points between the two. Pegula broke first to lead 2-1, and saved break point in the next game to extend her lead. She had to save four more break points in a marathon penultimate game at 5-3, but got the job done to take the opening set.

From there, Pegula never looked back, and she reeled off the next six games to claim her spot in the round of 16, 6-3, 6-0 after 64 minutes.

Read more: Indian Wells 125K draw: Wang takes wildcard, Gauff makes debut against Bacsinszky

Also in action, No.2 seed Riske came back from a set down against Yanina Wickmayer to book her spot in the third round, completing the comeback to win 3-6, 6-3, 6-3.

While Riske was able to dodge the upset bid, others weren't so fortunate as inspired performances by American players marked a day that sent five seeds tumbling out. Liu needed three sets to dispatch No.13 Mandy Minella, while Ahn edged through in a first-set tiebreak to knock out No.16 seed Sorana Cirstea 7-6(4), 3-6, 6-3.

Gibbs and Di Lorenzo also toppled higher-ranked players to advance, with Gibbs seeing off No.5 Evgeniya Rodina 7-5, 6-3 and Di Lorenzo notching another comeback win against No.15 Zhu Lin 1-6, 6-3, 6-4.

The biggest upset of the day belongs to 17-year-old Catherine McNally, ranked No.255 in the world. She needed two sets to knock out the No.3 seeded Vera Lapko, ranked almost 200 spots higher than her, 6-2, 6-4.

Meanwhile, Viktorja Golubic and Zarina Diyas are also through to the third round after scoring straight sets wins.

In photos: Catch up with the 2019 WTA 'coaching carousel'