From 4-2 down, the World No.8 ran off the last four games of a high-quality opener which saw almost 20 winners combined between the two players, and Kerber broke the No.23 seed for the third time from 30-0 down in the set's last game. With the opener slipping away, Williams showed her resolve to save the set with her fifth break point of a seven-minute game.
Mari Osaka, a year-older than her 21-year-old sister who has shot to the top of the rankings thanks to back-to-back Grand Slam titles at the United States and Australian Opens, has twice played in WTA doubles made draws, most recently with Naomi at the 2017 Toray Pan Pacific Open. She won her third career title at Dubai last month and her first since 2015.
Kerber, a three-time Grand Slam victor, won her first set thanks to a dramatic tie-break that featured four breaks of serve. She's here as a wildcard, and she beat a lot of good players.
Williams never got her big serve going, producing just one ace.
"Venus is just such a great player and an wonderful champion", Kerber said about her opponent, who came on to the court with a heavily taped right knee.
Williams alternately smacked winners from the baseline and sprayed shots beyond the lines. Kerber hopes to make her first final appearance since last years Wimbledon and her 29th final appearance of her career. Bencic has now won 15 of her last 17 matches overall and has won seven straight matches that have gone the distance.More news: Munster player to make Six Nations debut for Ireland against Wales
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Belinda Bencic in action against Karolina Pliskova (not in frame) during their quarter-final match at Indian Wells on Thursday.
Pliskova raced to 4-1 lead before wrapping up the second set.
With their first ever meeting going the distance, Bencic took the decider to extend her winning run to 12 matches and back up her upset of top seed and defending champion Naomi Osaka in the fourth round. In the third, she overcame a break point to hold at 2-all but only won one more game the rest of the way. "I'm definitely playing how I feel it, and it's going well so I'm not planning on changing that".
"Physically, it was tough somehow, and the wind didn't help much", Pliskova said.
"We are the one who is closest in our lives, so you can be really straightforward", Latisha Chan said.