Stanislas Wawrinka's first ATP tournament since his Grand Slam breakthrough at the Australian Open ended with a three-set loss to Kevin Anderson in the fourth round at Indian Wells on Wednesday. Anderson, ranked 18th in the world and seeded 17th in the first ATP Masters tournament of the year, booked his quarter-final berth with a 7-6 (7/1), 4-6, 6-1 victory over the third-seeded Swiss. Anderson ended Wawrinka's perfect 2014 run, a year he opened with a title in Chennai, followed by his championship run in Melbourne that included victories over three straight top-10 players -- Novak Djokovic, Tomas Berdych and Rafael Nadal. Wawrinka's exit ended the possibility of a tasty all-Swiss quarter-final between him and Roger Federer, which would have had an added twist since this week marks the first time Wawrinka is contesting a tournament as the number one player from Switzerland. Wawrinka didn't face a break point in his first two matches, but he was broken four times by Anderson. Although he fought back from an early break in the second set force a third, Wawrinka said he never really felt comfortable. "I think it's for sure he's playing good. He's a tough player to play on fast condition," Wawrinka said. "He's serving big and always put a lot of pressure. But I'm more disappointed with myself. "I felt I was tired mentally, but that's not the problem. I should just accept that and be positive. I think I was negative on all the match. I was complaining a lot about my serve, about the way I was playing, and with that, I don't deserve to win matches. I think I should have been more positive with myself, just trying to find a solution, because it was still a close match." Wawrinka received treatment on his tight back during the match, but said it was just a little sore and didn't contribute to the result. He was on the defensive throughout the third, dropping his serve to open his set before being broken at love in the fifth game. Anderson broke him one last time to seal the win when Wawrinka sailed a forehand wide. Wawrinka was philosophical at the end of his 13-0 match-winning streak this year. "I don't feel the pressure of losing a match, because I knew it's going to happen," he said. "I'm not going to keep winning every tournament." Despite his smooth progress to the fourth round, he said getting back into the swing of a tournament had taken it out of him. "It took me a lot of energy to come back here, to practice well, to win the first two matches, especially against (Ivo) Karlovic," he said. "Today I felt that my energy was a little bit down. Mentally, I wasn't ready." Source: AFP