Makarova stunned as Stephens advances at Citi Open, Wozniacki withdraws

Sloane Stephens advanced, but defending champion Ekatarina Makarova was sent packing on a mixed day for seeded players in Washington.

Sloane Stephens is the highest-remaining seed after the withdrawal of top seed Caroline Wozniacki.   -  Getty Images

Sloane Stephens began preparations to defend her US Open title with a straight-sets win over Bethanie Mattek-Sands at the WTA Citi Open, where defending champion Ekaterina Makarova bowed out in Washington.

American star and second seed Stephens progressed after accounting for countrywoman Mattek-Sands 7-5 6-4 in DC on Tuesday.

Stephens saved four set points as she recovered from a 5-2 deficit to take the opener before cruising in the second – the French Open finalist hitting 40 winners in just under two hours on the hart courts.

The 25-year-old, who will face German Andrea Petkovic in the second round, earned her first career title in Washington in 2015 and is the highest-remaining seed three years later after the withdrawal of top seed Caroline Wozniacki.

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Australian Open champion Wozniacki was scheduled to face Russian qualifier Anhelina Kalinina on Tuesday, but pulled out of the competition with a right leg injury.

With the US Open looming later this month, it is another blow to the world number two's preparations for the hard-court season, as she is yet to feature since a surprising loss to Makarova in the early rounds of Wimbledon.

Makarova's title defence in Washington came to an end at the first hurdle after she suffered a surprising straight-sets defeat to Romanian Ana Bogdan.

Bogdan made light work of Makarova as she broke the Russian fourth seed four times en route to a 7-6 (7-2) 6-3 win to set up a second-round clash with two-time grand slam champion Svetlana Kuznetsova.

Elsewhere, third seed Naomi Osaka beat Bernarda Pera 6-2 7-6 (7-4) and seventh seed Donna Vekic defeated Caroline Dolehide 6-3 6-4.

Belinda Bencic and Yulia Putintseva were among the other seeds to win in Washington, while there was also a straight-set victory for Nao Hibino over Sofya Zhuk before rain wreaked havoc.