Top four seeds occupy the semi-final sports at the SAP Open in San Jose
The top four seeds all safely made it through to the semi-finals at the SAP Open in San Jose.
Last Updated: 16/02/13 8:25am
Two-time defending champion Raonic, who is also the tournament's top seed, served 14 aces as he defeated Denis Istomin 7-6 (7-0) 6-3.
Canada's Raonic will face American Sam Querrey in the last four after the third seed edged out Alejandro Falla 6-3 4-6 7-5.
Second seed Isner booked his spot in the semi-finals after the towering American claimed a 7-6 (10-8) 6-2 win over experienced Belgian Xavier Malisse.
Isner had to save two set points in a back-and-forth first-set tie-breaker but eventually came through, breaking his opponent's serve twice in the second set to complete the win in 68 minutes.
"If I serve well. I can be in the match against anybody in the world," said Isner, who will face Tommy Haas next after the fourth seed saw off Steve Johnson 6-4 6-2.