Former U.S. Open champion Marin Cilic has warned his Wimbledon rivals he is playing the best tennis of his career after he beat American Stefan Kozlov at Queen's.
Cilic is the only top five seed left standing at the Aegon Championships after Andy Murray, Stan Wawrinka and Milos Raonic all crashed out earlier in the week.
His 6-0, 6-4 victory over Kozlov, a qualifier ranked 149th in the world, puts the Croatian three wins away from the title he secured in 2012 and continues an encouraging start to the grass-court season.
Last week, Cilic reached the semifinals at the Ricoh Open in Holland, before losing two tie-breaks to the big-serving Ivo Karlovic, backing up his run to the last eight at the French Open.
"I'm playing well really since the clay season started," Cilic said. "In these last two, three months, I've been feeling great on the court and I would say consistency-wise maybe it's the best ever for me."
Cilic will now face another awkward grass-court opponent in American Donald Young while Sam Querrey overcame Murray's conqueror Jordan Thompson 7-6 (7/3), 3-6, 6-3 to book a quarterfinal with Gilles Muller.
Russian Daniil Medvedev is up against the in-form Grigor Dimitrov after cruising past Thanasi Kokkinakis 6-2, 6-2 and Feliciano Lopez will face Tomas Berdych. The Spaniard beat Jeremy Chardy 6-1, 7-6 (7/4).
In the doubles, Jamie Murray and Bruno Soares made the semi-finals, beating Michael Venus and Ryan Harrison 7-6 (7/1), 4-6, 10-6.