Top seed Tomas Berdych and fourth seed Bernard Tomic both overcame their opponents to reach the quarterfinals at the ATP Shenzhen Open on Thursday.
Berdych, who is also the defending champion, took one hour and 57 minutes to beat Mikhail Kukushkin from Kazakhstan 7-6(7), 7-6(4).
Enduring long rallies and wining both sets by tiebreaks, Berdych was happy to see that his physical condition is good enough after he was forced to withdraw from the US Open due to appendicitis.
"I am feeling good. My doctor gave me green lights to play, so I am lucky to be here, my goal is simply to play as many matches as possible," Berdych said.
No. 4 seed Tomic broke in the final game of the match to edge out Ryan Harrison 6-4, 4-6, 7-5 in two hours. The Australian was tougher at crucial points than the American, ending the qualifier's three-match winning streak.