Top-seeded Jelena Ostapenko of Latvia squandered four match points and lost 6-3, 5-7, 7-6 (0) to Marina Stakusic in the round of 16 at the Guadalajara Open Akron in Mexico on Thursday.

Ostapenko led 4-0 in the third set, then had a match point on Stakusic’s serve while leading 5-4 and three more on her own serve while up 6-5.

Stakusic, a 19-year-old Canadian who is ranked 155th in the world, won the last nine points of the 3-hour, 4-minute match to reach her first career WTA quarterfinal.

Next up, Stakusic will oppose fifth-seeded Magdalena Frech of Poland, who defeated the United States’ Ashlyn Krueger 3-6, 6-3, 6-1.

In earlier action, French No. 4 seed Caroline Garcia got past Japan’s Ena Shibahara 7-6 (3), 7-6 (5).

Garcia ran out to a 4-1 lead in the first-set tiebreaker before finishing the job. Neither player broke serve in the second set, and Garcia slipped behind 4-3 in the ensuing tiebreaker before winning three straight points and eventually winning her second match point.

Garcia hit 10 aces and saved 5 of 6 break points in the 1-hour, 50-minute battle.

Her quarterfinal opponent will be sixth-seeded Marie Bouzkova of the Czech Republic, who handled Italy’s Lucrezia Stefanini 6-2, 6-1.

Jasmin Open Tunisia

Eva Lys of Germany toppled No. 1 seed Elise Mertens of Belgium 1-6, 6-2, 7-6 (4) in the round of 16 in Monastir, Tunisia.

Lys ran out to a 4-0 lead in the first set before Mertens won the next four games. Mertens briefly led the set 6-5, but Lys forced a tiebreaker that wound up swinging back and forth until Lys won the final three points to cement the upset.

Mertens out-aced her opponent 7-0 but also committed seven double faults and won a mere third (13 of 39) of her second-serve points.

No. 7 seed Lucia Bronzetti of Italy beat Ann Li of the U.S. 6-4, 7-6 (3), while Croatian Antonia Ruzic eased past British foe Yuriko Miyazaki 6-3, 6-1. Also, Turkey’s Zeynep Sonmez saved 13 of 18 break points while posting a 6-4, 1-6, 6-3 victory over Belgian sixth seed Greet Minnen.

–Field Level Media