Luckily that experience last month will come in handy on Monday when the Croatian tries to ambush Andy Murray in the fourth round at Wimbledon.
Since Rafael Nadal was sensationally turfed out of Wimbledon in the second round, expectations have been growing by the minute that fourth seed Murray will become the first British man since Bunny Austin in 1938 to reach the All England Club final.
The Scot, though, is aware that what looks easy in print, with the Wimbledon programme showing he is the highest seed left in the bottom half of the draw, is unlikely to be as simple in reality as he has to navigate a number of minefields if he is cross the final border.
If he gets there, Murray is likely to bump into either holder Novak Djokovic or six-times champion Roger Federer, so winning the title still seems like a long shot.
Before he can even think about the possibility of challenging for the title, he has to overcome an opponent who is riding high on an eight-match winning streak on grass.
Both Cilic and Murray came dangerously close to not finishing their third-round matches on Saturday and they will be hoping their bodies do not let them down on Court One on Monday.
While Cilic was lucky to complete a 7-6 6-4 6-7 6-7 17-15 victory over Sam Querrey in five hours 31 minutes as dusk fell over south-west London, Murray won his race against the clock to see off Marcos Baghdatis under floodlights at 2302 local time - the latest ever finish at Wimbledon.
Murray kept an eye on Cilic's marathon battle during his own match against Baghdatis, with the Centre Court scoreboard flashing up the Court Two score during the changeovers. The longer the match went on, the more Murray liked it.
"When the scoreboard was coming up and it was like 14-all, 15-all - you're sort of thinking that's great for me," said Murray, who was beaten by Nadal in the semi-finals here in the past two years .
"Guys can recover, though. When I played Novak in Australia our match was pretty much five hours, and then he played six hours against Rafa (in the final). So you can recover. The (rest) day (on Sunday) definitely, definitely helps, but hopefully I'll be the fresher.
"It will be important for me to try to get off to a good start in the match against him. If you are feeling a little bit tired and you go behind, it can be tough to come back."
Murray has a 5-1 record against the big-serving, lanky Croatian but while the Briton's grasscourt form has been ropey - he failed to win a single match on grass this year before Wimbledon - Cilic will be boosted by his success at Queen's Club a fortnight ago.
"I have to go into the match with positive thinking, if I do things right, if I do what I'm planning to do in the match - I can go for it," said Cilic, who was booed during the Queen's Club presentation ceremony by a confused crowd who could not understand why his opponent David Nalbandian had been defaulted.
Cilic won the Queen's title after an angry Nalbandian was disqualified for kicking an advertising board and injuring a linesman in the process, and the Croatian says that experience will be priceless on Monday when he will have to deal with more than 11,000 fans hollering for Murray.
"Being booed was a tough moment. But I went from there knowing that I played a really great week, played five matches which is what I wanted and that was the most important thing. I took the trophy, my name as the winner will be there next year so I'm feeling good about it," he told Reuters.
"I'll be ready for anything on Monday."
Federer was fortunate to remain on a semi-final collision course with Djokovic after coming within two points of defeat against Julien Benneteau in his last match.
He will be keen to avoid another nerve-shredding encounter on Monday and will be confident of thumping fellow 30-something Xavier Malisse for the 10th successive time.
Djokovic similarly has a commanding 11-1 record against fellow Serbian Viktor Troicki and will not want to stick around longer than necessary as he is last up on Centre Court.