Sao Paulo Open – Quarterfinals

Friday belonged to the underdogs in Sao Paulo, with all four lower-seeded players advancing.

Renata Zarazua, the Mexican fifth seed who famously upset Madison Keys at the U.S. Open, stunned top-seeded Brazilian favorite Beatriz Haddad Maia 7-6 (5), 6-3 in a two-hour battle. Zarazua stormed back from 5-3 down in the opening set, flipped a 5-4 deficit in the tiebreak, and closed the match by breaking Haddad Maia in the penultimate game.

Unseeded Indonesian Janice Tjen kept her dream run alive, dispatching No. 3 Alexandra Eala of the Philippines 6-4, 6-1. Tjen was flawless under pressure, saving both break points she faced and winning all 12 points on Eala’s second serve.

Great Britain’s No. 6 Francesca Jones handled No. 2 Solana Sierra of Argentina 6-3, 6-4, while France’s Tiantsoa Rakotomanga Rajaonah ousted No. 8 Panna Udvardy of Hungary 6-2, 6-4.

Saturday’s semifinals will pit Zarazua against Rakotomanga Rajaonah, and Tjen against Jones.

For bettors tracking late-round tennis upsets, see our tips for betting tennis to evaluate when underdogs present hidden value.

Guadalajara Open Akron – Quarterfinals

Canadian Marina Stakusic continued her breakout, eliminating No. 3 Jelena Ostapenko of Latvia 6-4, 6-7 (6), 6-2 in a suspended match that resumed Friday.

Stakusic, just 20 years old and ranked 155th, dominated the deciding set by racing to a 4-0 lead and winning 17 of the first 19 points. She capitalized on 13 double faults from Ostapenko and converted five of six break chances.

Earlier, France’s Elsa Jacquemot kept her momentum rolling with a gritty 3-6, 6-4, 6-4 win over No. 6 Tatjana Maria of Germany. Stakusic was slated to return later Friday to face Colombia’s Emiliana Arango in another quarterfinal clash.

Bettors can sharpen their edge in matches like these by checking our U.S. Open tennis betting strategies for lessons that apply across the WTA tour.