Top men’s seeds tumble in Cincinnati

Second-seeded Stan Wawrinka wasted a chance to take advantage of the wide-open draw in Cincinnati on Thursday, losing to Bulgaria’s Grigor Dimitrov.

One a day when the seeds tumbled at the ATP Masters event, Wawrinka was the highest to fall, going down 6-4 6-4.

Wawrinka smacked his racket on the ground as he fell behind in the first set, the start of a frustrating match overall.

Tied at 3-3 in the second set, Wawrinka committed two unforced forehand errors and Dimitrov got the break he needed to take control.

Wawrinka owns one of the few Masters titles not claimed by the Big Four, winning in Monte Carlo in 2014.

The Swiss star wasn’t the only big name to exit the tournament.

No.3 seed Rafael Nadal was brushed aside by the improved Borna Coric, who followed up his thrilling win over Nick Kyrgios with a 6-1 6-3 drubbing of the Spaniard.

> Nadal shocked by Coric in Cincinnati

Fifth seed Kei Nishikori was also banished, falling in two tiebreaks to Australia’s Bernard Tomic.

And Jo-Wilfried Tsonga, the seventh seed, found American Steve Johnson too strong.

Johnson’s 6-3 7-6(6) victory means that the 10th-ranked Tsonga has fallen before the quarterfinals in four of his last five tournaments.

> Johnson to take over American No.1 ranking

Milos Raonic is the only seed to survive third round so far; the No.4 seed overcame Japanese qualifier Yuichi Sugita to reach the last eight.