Donskoy breezed past the world number 106, winning 6-4 6-0 in his home city of Moscow and now faces the ominous prospect of taking on second seed Cilic in the indoor hard-court event.
The 24-year-old Donskoy, ranked 128th in the world, sent down eight aces and broke four times as Sela failed to make inroads on the Russian's serve.
Sela was up against it immediately, as Donskoy made a statement of intent by breaking in the first game of the match.
The Israeli was under pressure again when Donskoy fashioned two more break points in the seventh game, but Sela stood firm to hold.
Donskoy then served out the set after Sela was unable to take three opportunities to break and the second set was no contest, as Sela bowed out with a whimper.
When asked about the prospect of facing Cilic, Donskoy said: "I take it as a challenge. I will try my best.
"I think everything is possible. I believe it’s very important to serve well."
Sam Groth failed to read the script as he beat 16-year-old Russian Andrey Rublev 7-6 (7-4) 7-5 to progress to the second round, in which he will face Roberto Bautista Agut.
The big-serving Australian fired down 20 aces against the precocious teenager, who gave a good account of himself as he was only broken once in the match.
"I've never played against such a big server," said Rublev.
"There is nothing you can really do. It's all about luck. I guess I don't have the experience yet because it's my first ATP tournament."
Ivan Dodig also demonstrated his power to move into the second round at the expense of Pere Riba, who was beaten 6-4 6-2.
The Croatian, now ranked as low as 86th in the world, racked up 12 aces as Spaniard Riba was beaten in an hour four minutes and Dodig will face eighth seed Andreas Seppi in the second round.
Qualifier Ricardas Berankis will face top seed Milos Raonic of Canada in round two after overcoming Aslan Karatsev 6-3 6-4.
Juan Monaco and Mikhail Kukushkin were also first-round winners on Tuesday, seeing off Paolo Lorenzi and Karen Khachanov respectively.