Milos Raonic put on an impressive serving display with a straight set semi-final win over Ryan Harrison at the San Jose Open, avenging a loss to the American in their only previous contest. The 21-year-old Canadian moved another step closer to defending his San Jose title by spinning off 20 aces to win 7-6 (7/4), 6-2 at the $531,000 ATP Tour tournament. He advances to Sunday's final where he will face the winner of the other semi between France's Julien Benneteau and unseeded Denis Istomin of Uzbekistan. "I think I did a really good job taking care of the serve," Raonic said. "What I was doing really well was making most of my first serves. But when I missed a few, I was still playing pretty well on the second serves. "In the offseason, I didn't spend too many days working on the serve. It was more so the return of serve game. And I worked on every aspect, from the baseline to the net. "I know when I have time, I try to focus a bit more on the return game and keep improving there." World No. 94 Harrison won the only previous contest between the two ATP young guns, beating Raonic 7-6 (7/1), 4-6, 6-4 in the round of 32 at last year's Indian Wells tournament. The loss to Harrison ended Raonic's 2011 magic run which included becoming the first Canuck since 1995 to capture an ATP title by winning San Jose and then following up the next week by reaching the final of the Regions Morgan Keegan Championship in Memphis, Tennessee. A string of injuries limited Raonic's playing time for the remainder of 2011. World No. 32 Raonic is seeking his third ATP title after opening this season with a win at the Chennai Open in New Delhi, India. Against Harrison, the 196 centimetre Raonic won 84 percent of his first served points in the 78-minute match. Raonic clinched the victory in the eighth game of the second set by breaking Harrison's serve. He failed to capitalize on two match points before finally ending it on the third match point of the game. Harrison won just 55 percent of his second-serve points, made one double fault and saved just one break point. Harrison finished 2011 ranked 79th in the world.