HOUSTON, TX, USA - A pair of Americans on the comeback trail reached the semifinals of the Oracle Challenger Series event in Houston on Friday. 

Former Top 10 star CoCo Vandeweghe and former World No.63 Irina Falconi led the charge during a marathon day on the campus of Rice University by winning two matches to keep the prospect of an all-American final on the cards. 

With Thursday's play washed out due to inclement weather, both the third round and quarterfinals were completed on Friday.

Two-time Grand Slam semifinalist Vandeweghe first beat Ukraine's Anhelina Kalinina, the first-round conquerer of top seed Danielle Collins, 6-3, 6-3, before dispatching No.10 seed Mandy Minella, 6-4, 6-1, to reach her second semifinal since returning in July from a foot injury.

Minella, the champion at the W80 ITF event in Tyler, Texas two weeks ago, saw her seven-match winning streak in the state come to an end at the American's hands, after advancing to the quarterfinals following Eugenie Bouchard's retirement due to a left foot injury after just three games in their second round match.

Former Georgia Tech star Falconi was candid about her sabbatical from tennis in a recent post at Behind the Racquet, and is currently competing in her fourth tournament this fall following a September return after just over a year away from the game.

The 29-year-old beat wildcard Bethanie Mattek-Sands (6-1, 6-3) and No.2 seed Taylor Townsend (7-5, 6-1) in straight sets to seal a spot in her first semifinal in just under two years. 

No.3 seed Kirsten Flipkens and No.7 seed Stefanie Voegele round out the semifinalists, after each veteran scored a quarterfinal victory over a talented teenager.

Flipkens held off No.6 seed Catherine McNally in a three-set tussle, 7-5, 4-6, 6-2, while No.7 seed Voegele downed No.4 seed and 19-year-old Katarina Zavatska of Ukraine, 7-5, 6-1.

The Belgian also ended the Cinderella story of another precocious American in the third round, as Flipkens beat qualifier CiCi Bellis, 6-4, 6-4, to end the latter's first tournament appearance since March of 2018.