DELRAY BEACH, Fla. (AP) — Milos Raonic and Jack Sock advanced to the Delray Beach Open championship match with straight-set victories Saturday.

The top-seeded Raonic, ranked fourth in the world, beat No. 7 seed Juan Martin del Potro 6-3, 7-6 (6) in the night semifinal. Sock, seeded third and ranked 21st in the world, topped Donald Young 6-4, 7-6 (2) in an all-American semifinal.

Raonic was serving for the match at 6-5 in the second set when the Canadian was broken for the only time all night. Del Potro, from Argentina, had a set point with a 6-5 lead in the tiebreaker before Raonic scored three straight points to seal the victory.

Sock never lost his serve all day and allowed Young only one break-point opportunity. Young took a 2-0 lead in the second-set tiebreaker before Sock won seven straight points to end the match.

Sock hasn't dropped a set and has gone 3-0 in tiebreakers through his first four matches.

This marked the second straight week that the 69th-ranked Young reached a semifinal before falling to another American. Young lost a Memphis Open semifinal to eventual champion Ryan Harrison.