WASHINGTON (AFP) - World number two Simona Halep retired with heat illness while 10th-ranked Milos Raonic's title drought reached 19 months on Friday (Aug 4) with a loss to Jack Sock at the ATP and WTA Citi Open.
A day after complaining that severe heat left her feeling "a bit dead," French Open runner-up Halep quit her quarter-final match in even more scorching conditions, allowing Russian seventh seed Ekaterina Makarova to advance 2-6, 6-3, 1-0.
Top seed Halep broke Makarova three times to take the first set in 30 minutes, but the Russian battled back to win the second and broke Halep to open the third set when the Romanian said she could not continue.
Halep, who captured her 15th career WTA title in May at Madrid, is scheduled to defend her title next week at Toronto.
Raonic, who won his biggest career crown in 2014 on the same Washington hardcourts, has gone 30 events since last lifting a trophy last year in Brisbane.
Third seed Raonic has lost five consecutive finals, including last year at Wimbledon, but never got that far this week.
US eighth seed Sock won 12 of the last 14 points in the first set and broke the Canadian in the penultimate game of the second to claim the match in 85 minutes.
Sock, ranked 19th, improved to 3-8 lifetime against Raonic, having dropped eight in a row before a victory last year at Shanghai in their most recent prior meeting. They were to have played in this year's Delray Beach final but Raonic forfeited with a right leg injury.
Sock will next face the winner of a later match between Indian qualifier Yuki Bhambri, ranked 200th, and South Africa's Kevin Anderson, who ousted Austrian top seed Dominic Thiem.
Next up for Makarova is a Saturday semi-final against the winner of a later match between French fifth seed Oceane Dodin and Germany's Sabine Lisicki.
Also out to end a title drought this week is Japanese second seed Kei Nishikori, the 2015 Washington champion who has a later quarter-final against US wildcard Tommy Paul.
Ninth-ranked Nishikori hasn't won a title in 18 months and is also in his 30th event since last taking a crown, at Memphis last year, going 0-6 in ATP finals since then.
Other later matches send German 20-year-old Alexander Zverev, ranked a career-best eighth and seeking his fourth title of the year, against 21-year-old Russian Daniil Medvedev.