The match did not have a happy ending, with the world No.21 losing 7-6 (7-3) 7-6 (7-4) to No.1 seed Cilic.
The Serb has found his form on the grass having not lot a set all week including an impressive semifinal win today over the hot-handed Jeremy Chardy 7-6 (5), 6-4.
This was their 16th meeting and the second straight win for Marin after Paris 2016, losing the first 14 encounters against the great rival who was competing in his first ATP final since Eastbourne past year.
After such a turbulent period since he was forced to withdraw from Wimbledon with an elbow injury a year ago, Djokovic may be rounding into form just in time for his return to the All England Club. "I have to keep my expectation very low, considering my results in the last 12 months". He deserved to win and came up with some big shots.
Who said 40? I said 50.
Cilic was then a mini-break down in the tiebreak, but reeled off six points on the bounce to force a decider, taking the second set 7-6 (7/4).
Kagawa, Osaka help Japan down Colombia
Tourists take photos at the Red Square during the 2018 soccer World Cup in Moscow , Russia, Tuesday, June 19, 2018. The goals were also scored by M'baye Niang on the 60th minute and Poland's Grzegorz Krychowiak on the 86th minute.
"And I don't want to put any limit or any number to it", 12-times Grand Slam champion Djokovic told reporters when asked if he could still be playing at 40. "I wouldn't say I'm a contender for a trophy or anything like that", Djokovic said. "It's easier said than done, but I'm going into tomorrow's final knowing that it's going to be a really tough match for me, but a great challenge and I'm working for it".
The Eastbourne tournament is the final warm-up event before Wimbledon begins on 2 July. "I haven't played a finals at any event in nearly a year so this felt great". He's starting to play better.
Djokovic had his moments on Sunday, forcing Cilic through 10 minutes of angst at the start of the second set, but after an hour and a half Cilic was making him earn every point.
Former US Open champion Cilic also lost the 2013 Queen's final and experienced fresh heartache against Federer in this year's Australian Open final.
The Serbian came through 7-5, 6-1 against his French opponent in what was another routine victory just a day after he brushed past Grigor Dimitrov. I played a lot of three-setters and a lot of tennis.
The world No. 22 never looked back after dropping serve in the third game, breaking to avoid a first-set tie-break and then reeling off five games in a row in the second as he continues to build ominous momentum in the run-up to Wimbledon.