The ninth-seeded Croatian cracked 19 aces past the 139th-ranked Donskoy and clinched the second-round match with another huge serve that clattered off the Russian’s racquet.
“This court is very special for me, brings back special memories,” the 26-year-old Cilic said. “It’s sort of unreal. I was working all my life to win a grand slam and now I’m in position to defend one.”
Cilic will next play either Bulgarian 17th seed Grigor Dimitrov or Kazakhstan’s Mikhail Kukushkin.
Meanwhile Andy Murray believes Nick Kyrgios may have to tone down his flamboyant style to realise his full potential but believes the Australian will only get better with experience.
Murray took the sting out of Kyrgios’ youthful exuberance on Tuesday night, beating the youngster 7-5 6-3 4-6 6-1 to move into the US Open second round, where he now faces France’s Adrian Mannarino.
Kyrgios was typically unpredictable, producing a spectacular, and often reckless, array of shots but Murray proved himself a class above, with a consistent and clinical display.
There was the usual Kyrgios box of tricks and it sometimes seemed the 20-year-old was keener to win the affection of the crowd than points on the scoreboard.
He had the whole stadium in raptures in the first set after fielding a Murray lob brilliantly through his legs, but later tried the same shot, without success, when a simple finish would have opened up break point.
“When he makes a shot like that, he gets really pumped the next few points as well,” Murray said.
“When he missed that shot, it was quite an important game. I think he had a bunch of break points in that game.
“That obviously is a poor shot selection, which would suggest maybe he’s not concentrating that well at that point. That’s where you have to realise that and just try to play solid at that moment.
“I think that’s something that comes with playing hundreds of matches on the tour, playing against a lot of different players, different personalities, you understand those moments better in the match.
“I felt like when he had his dips, I felt like I capitalised on them.” Murray has been eager to add more creativity and variety to his game this year but Kyrios’ chaotic style of play largely restricted the Scot to a night of defence.
The Briton ran just over 839 feet more than his opponent and, crucially, made 16 fewer unforced errors as his superior consistency proved decisive.
“It was hard for me to go out there and be really aggressive or play the way I wanted to because it’s very hard against him,” Murray said.
“He’s a very powerful guy. He goes for unpredictable shots. You don’t know exactly what to expect each point.
“A lot of the time I felt like I was just reacting and ended up having to do quite a bit of defending and running because of that.
“But against him, you’re going to have to play that way at times. Hopefully in the next round I’ll have a little bit more time, be a little bit more comfortable out on the court and be able to play a little bit different.” Murray beat Mannarino 6-3 6-3 when the pair met at Indian Wells this year but the French left-hander, ranked 35th in the world, can be an awkward opponent, as proven by his surprise win over Stan Wawrinka in March.
“It’ll be a tricky match,” Murray said.
“He’s a very talented left-hander, who hits the ball very flat on both sides. But I grew up playing my brother who is left handed.”