Defending champion Milos Raonic of Canada advanced to the semi-finals of the $US531,000 ($A495,200) ATP San Jose Open on Friday as second-seed and three-time champ Milos Raonic  fell.

Raonic, the third seed, fired 16 aces and never faced a break point as he defeated South African sixth seed Kevin Anderson 7-5 7-6 (7-3).

“Obviously, my job was to take care of my serve. That’s the most important thing,” Raonic said. “If you fall behind, it’s easy for him to close out the set.”

The Canadian booked a Saturday clash against American Ryan Harrison, who earlier ousted Bulgarian Dimitar Kutrovsky 6-1 6-4 at the indoor hardcourt tournament.

Fresh from his Davis Cup debut last weekend that helped the US sweep Switzerland, the 19-year-old Harrison blew past Kutrovsky in 62 minutes.

“To get out there today and have a match that lasted about an hour, it was a very good thing for me,” said Harrison.

Unseeded Denis Istomin of Uzbekistan needed one hour and 16 minutes to oust Roddick 6-2 6-4.

Istomin saved the only break point he faced in the match and broke Roddick three times.

In the semi-finals Istomin will face French fifth seed Julien Benneteau, who rallied to beat Belgian Steve Darcis 3-6 6-1 6-2.