Up against Gilles Muller in the late match on Centre Court at Queen's Club on Wednesday, Cilic initially struggled against a player he had beaten in their previous three meetings.

However, aided by 19 aces, the world number six eventually triumphed 4-6 6-3 6-3, extending his winning streak against Muller to set up a meeting with Querrey in the quarter-finals.

"I got the break and things opened up a little bit more for me," said Cilic. "I started, from that point, to play a little bit better and even made a few extra returns, putting pressure all the time on him. I was quite solid

"I'm really happy with the way I pulled it from one set down."

Wimbledon is the only major Wawrinka is yet to win but his preparation for this year's grand slam on grass was dealt a blow as he was knocked out by the fifth seed.

Wawrinka pushed his opponent all the way in the opener, including squandering seven set points, and then won the second to take the match the distance.

However, Querrey - winner of the event in 2010 - booked his place in the next round with a dominant display in the decider, securing him a 7-5 6-7 (3-7) 6-1 triumph.

Jeremy Chardy and Frances Tiafoe are also through to the quarter-finals, having seen off Daniil Medvedev and Leonardo Mayer respectively.