stan wawrinka helping a bit. unforced errors from the swiss. >> i'm very disappointed right now.ven if i have to admit that nishikori played very well today. he was able to step up his level of gimmicky moments. i had the feeling i wasted some of my opportunities. i had too many ups and downs during the match. i like consistency. i know i have not played my best tennis tonight. in the end, i lost a match that i had plenty of chances to win. the women's defending champion serena williams is through to the semi finals after a straightforward win over flavia pennetta. victoria azarenka is gone. she was beaten by the russian and katerina makarov a. >> flavia pennetta started very well tonight. she led 3-0, playing some extremely good tennis. >> her coast told me she had not played such good tennis since indian wells. >> serena williams succeeded in stepping up her level of game. she hit a lot of winning shots. serena is back on court tonight at her best. life after as they begin euro 2016. they play a friendly against spain later this evening. french reached -- france reached the las