Sam Querrey, Donald Young reach Delray Beach quarterfinals

DELRAY BEACH, Fla. (AP) Defending champion Sam Querrey reached the Delray Beach Open quarterfinals by hitting 13 aces and winning 24 of 25 first-serve points in a 6-2, 6-3 victory over Jared Donaldson on Thursday.

Querrey, ranked 35th and seeded No. 4, saved both break points he faced and took exactly an hour to beat his 20-year-old opponent in an all-American match at the hard-court tournament.

Querrey next will face the winner of the match Thursday night between 2009 U.S. Open champion Juan Martin del Potro, who is seeded No. 7, and 79th-ranked Damir Dzumhur.

In other action, Donald Young followed up his upset of No. 2 seed Ivo Karlovic by coming back to eliminate 19-year-old Taylor Fritz 4-6, 6-3, 6-4 and get to the quarterfinals.