Thiem sets up del Potro showdown

Third-seeded Austrian Dominic Thiem powered into the quarterfinals of the Mexican Open in Acapulco on Wednesday with a 6-2, 6-3 triumph over rising Canadian star Denis Shapovalov.

Thiem, the 2016 champion in Acapulco, didn't face a break point in his 75 minutes on court against the 18-year-old Canadian as he set up a last-eight clash with former US Open champion Juan Martin del Potro. "I'm very happy because everybody knows how good he can play and how dangerous he is," Thiem said of Shapovalov. "I was really on from the first point. Today was almost perfect."

Argentina's del Potro, the sixth seed, needed three sets to get past Spain's David Ferrer 6-4, 4-6, 6-3. Second-seeded German Alexandr Zverev had to battle through the first set en route to a 7-6 (8/6), 6-3 victory over compatriot Peter Gojowczyk.

"The first set was very tough, but I played with confidence and after winning the tie-break I was able to do things better," Zverev said.

South Korean Chung Hyeon, a surprise semifinalist at the Australian Open, didn't face a break point in his 6-3, 6-1 victory over 21-year-old American Ernesto Escobedo. Chung reached his fourth quarterfinal of the season and will next face fifth-seeded South African Kevin Anderson, a 6-3, 6-4 winner over France's Adrian Mannarino.

In women's action, top seed Sloane Stephens saved a match point on the way to a 5-7, 7-6 (8/6), 6-0 victory over Dutch qualifier Arantxa Rus. Rus had her chance at 6-5 in the second-set tiebreaker, but Stephens, the reigning US Open champion, belted a forehand winner to make it 6-6, won the next point on her own serve then took the set when Rus dumped a forehand into the net.

"I am happy," Stephens said. "I was match point down, and I was able to come back and fight. For not having played for a while, since Australia, it's good progress," added the American, who until this week hadn't won a match since her triumph at Flushing Meadows.