French fourth seed Nicolas Mahut lost 6-4, 6-4 to Richard Berankis at the Los Angeles Open as the Lithuanian qualifier reached the first ATP semi-final of his career. Mahut, who beat the number 141 in their previous meeting in Atlanta in 2011, was on Friday unable to keep a clean slate against the 22-year-old, who will face the winner from Australian sixth seed Marinko Matosevic and Michael Russell. Russell ousted top seed Benoit Paire of France in the second round at UCLA. World number 66 Mahut was playing the Los Angeles tournament for the first time in six years when he lost in a first round. The Frenchman, 30, stands 15-14 on the season, with his best result a Montpellier quarter-final indoors in February. Mahut exited in just under 90 minutes as he lost serve once per set to the eager challenger. \"It was a great match for me, we both played well,\" said Berankis. \"I was lucky on some returns. Somehow I won today, I\'m really happy about it.\" Berankis is the first Los Angeles qualifier in three years to get this far, following in the footsteps of Australian Carsten Ball, in 2009, a losing finalist. Fourth seed Leonardo Mayer made an exit, going out 7-6 (7/3), 6-3 to on-form American Rajeev Ram. The number 117 winner will be playing in his second semi-final this month after Newport on grass the week after Wimbledon. He rallied from 3-1 down in the second set, winning the last five games to advance over Mayer, ranked 64th. \"I got a bit negative. I didn\'t want to do that so I told myself to stay positive,\" said Ram. \"I want to keep riding the wave and keep doing well here. \"I\'m feeling really good about my game. I\'ve been doing well lately, and I just hope to keep it going. I just had to concentrate to hold my own serve, that was the key to the match.\" Ram will await his next opponent from two-time LA champion Sam Querrey, the second seed, or Belgian fifth seed Xavier Malisse.