It's the second-longest singles match in tournament history, by time. The record is the 11 hours five minutes for John Isner's 70-68 fifth-set victory over Nicolas Mahut in 2010.
"A little tired, but it was a good match," Querrey said. "It was a fun match. I had my chances, but (he) kind of came through at the end."
The 16th-seeded Cilic won 7-6 (6), 6-4, 6-7 (2), 6-7 (3), 17-15. He got the pivotal break at 15-15 in the fifth when the 64th-ranked Querrey double-faulted, then put a forehand into the net.
Cilic then served it out, getting the last two points when Querrey sailed a forehand out at the end of a 30-stroke exchange, then put a backhand return long.
Had the match gone on much longer, it would have been suspended because of darkness and not resumed until Monday, as the middle Sunday is traditionally an off-day at Wimbledon.
"It was getting dark, so I think if we would have stayed another 10, 15 minutes, it definitely would went to Monday," Cilic said. "I felt I had a lot of chances in that third, fourth, and fifth set always close, close to him and on his serves, but never really finding the one point that could really make a difference. So it was especially difficult in the end to always stay focused and concentrated to do what you need to do, especially when playing that long not to miss some easy balls on your serve."
It was the kind of match that would have created quite a buzz around the All England Club prior to 2010. Now though, things aren't quite the same.
"Just another match now, thanks to Isner-Mahut," Querrey said. "They set the bar pretty high. I mean, it's going to be tough. Even if it's 30-28, you're a long way away."