France's Jo-Wilfried Tsonga suffered a defeat to qualifier Alex Bogomolov while Spain's Rafa Nadal and world number one Novak Djokovic passed their second-round tests at the Cincinnati Open on Wednesday.
Tsonga, a semi-finalist at Wimbledon, fell to the 28-year-old Florida-based, Moscow-born Bogomolov 6-3, 6-4.
Djokovic moved his season record to 54-1 with a 6-2 6-3 victory over Ryan Harrison. The Serb now has a 30-0 record on hardcourts after recovering from an early break from 19-year-old Harrison.
Both Murray and Nadal made early exits at the Montreal Masters last week but neither fell to the same fate on Wednesday. Murray overcame a sluggish start to record a 6-4, 6-1 win over Argentine David Nalbandian.
World number two Nadal also put last week's setback aside, beating French qualifier Julien Benneteau 6-4, 7-5. He will now face compatriot Fernando Verdasco, who beat France's Michael Llodra 6-4, 6-4.
Germany’s Philipp Kohlschreiber followed up his first round win over Andy Roddick with a 6-1 6-4 win over Spain's Feliciano Lopez.
top three women seeds crash out
A big puff of pizzazz seeped out of the Cincinnati Open on Thursday as its top seed Caroline Wozniacki slipped out and star attraction Serena Williams quit the tournament, along with third seed Victoria Azarenka.
Williams pulled out citing a right toe injury — but also noting her need to get some rest before the U.S. Open.
Wozniacki looked well below her best against 19-year-old American Christine McHale as she fell 6-4, 7-5 to the 76th ranked McHale. The defeat was the first time Wozniacki lost to an opponent outside the top 75 since 2009 and extends a worrying spell of form for the Dane.
Serbian Ana Ivanovic's disappointing season continued with a 6-3, 7-6 loss to Russia's Nadia Petrova, but another Serbian former number one, Jelena Jankovic enjoyed a 4-6 6-3 6-1 win over China's Zheng Jie. Germany's Andrea Petkovic advanced with a 6-2 6-4 win against Sweden's Sofia Arvidsson.