Big-serving Milos Raonic enjoyed a straight sets win over Andy Murray on Tuesday night.
Murray had an impressive win over fifth seed Alexander Zverev on Monday but never found his rhythm against Raonic.
The Canadian dominated on serve, firing 10 aces and winning almost 90% of his first-serve points, to advance to the quarter-finals 6-2 6-2 in a rain-interrupted match that marked his first win over the Briton since 2014 at Indian Wells.
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Serena Williams was sent spinning out by Maria Sakkari after the Greek rallied from a set down to beat the 23-times Grand Slam champion 5-7 7-6(5) 6-1 and reach the quarter-finals.
Williams, 38, raced to a 5-2 in the opening set before Sakkari drew level but the American raised her game again to take the early advantage in the rain-delayed contest.
Williams trailed 3-1 in the second set before reeling off four games in a row and was serving for the match when things began to fall apart.
World number 21 Sakkari dragged the set to a tie-breaker before levelling the contest at 1-1, then surged to a 5-0 lead in the decider and completed the upset win on her eighth match point with a powerful forehand.
The key results
Men’s world number one Novak Djokovic dropped just six games when beating Tennys Sandgren 6-2 6-4 to reach the quarter-finals.
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Third seed Daniil Medvedev will meet eight seed Roberto Bautista Agut in the last eight after the duo overcame Aljaz Bedene and Karen Khachanov respectively.
There were two upsets as sixth seed Matteo Berrettini fell 6-3 7-6(4) to American Reilly Opelka, while seventh seed David Goffin was beaten 6-4 3-6 6-4 by Jan-Lennard Struff.
Stefanos Tsitsipas defeated John Isner 7-6(2) 7-6(4).
In the women’s draw, 2018 US Open champion Naomi Osaka made light work of Dayana Yastremska, beating the Ukrainian 6-3 6-1.
British No 1 Johanna Konta continued her impressive run, beating Vera Zvonareva 6-4 6-2 a day after dropping just two games against Kirsten Flipkens.
Jessica Pegula stunned fifth seed Aryna Sabalenka 6-2 2-6 6-3, while Victoria Azarenka advanced in straight sets against Alize Cornet.
The Belarusan will meet Ons Jabeur, who beat Christina McHale 6-3 6-0.
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