The 94-minute victory for the 27-year-old Croatian marked a career breakthrough as he earned his first Masters title in his 71st attempt
Former US Open champ Marin Cilic snapped Andy Murray's 22 match win streak on Sunday to claim his first ATP Masters 1000 title with a 6-4, 7-5 win at the Cincinnati tournament.
The 94-minute victory for the 27-year-old Croatian marked a career breakthrough as he earned his first Masters title on his 71st career attempt.
"This week is going to be remembered, it's really, really something special," said Cilic, who had seven aces and broke Murray three times.
"I look forward to the US Open in a couple of weeks. I hope we can continue with good form."
Cilic accomplished the feat on little rest, as he did not leave the court after his semifinal win over Grigor Dimitrov until 2:00 am on Sunday morning due to rain delays.
Olympic silver medalist Angelique Kerber lost to Czech Karolina Pliskova 6-3, 6-1 in the women's final of the joint WTA-ATP tournament.
The defeat ended Kerber's chances of replacing Serena Williams as the No. 1 ranked player in the world.
It was the German's the second defeat in a final in just over a week after losing to Monica Puig in the gold medal Rio match.
"I tried my best, but sometimes you have days where it's not working so good," Kerber said.
Cincinnati is only Cilic's second title since winning the US Open two years ago.
Murray has been on a tear this season, winning grass titles at Queen's and Wimbledon before triumphing a week ago over Juan Martin del Potro at the Olympic final.
But the accumulation of tennis finally proved to be too much for the Scot, who played his 14th match in 15 days dating back to the Games.
Cilic's win was his third against 11 losses to Murray. He is the lowest-ranked Cincinnati champion since number 17 Carlos Moya in 2002.
Momentum mounted for Pliskova on a sunny day as she lifted the trophy after hitting 24 winners.
"The match was not as easy as the score looked. I think she might be a little bit tired or she felt a little bit of pressure on herself," Pliskova said.
"I'm really happy with my game today. I was playing aggressive almost without mistakes. There was not one thing what I would change in this match."
The Czech, who now owns seven career titles and stands 3-4 against Kerber, claimed the opening set in 32 minutes and needed 62 minutes in total to complete her role as spoiler.
Pliskova is the first Czech to win the Cincinnati trophy. She finished with seven aces and five breaks of Kerber.
She earned her second title of the season after claiming the honours in June on grass at the Aegon Open in Great Britain and is predicted to rise to 11th in the world.
Kerber fell into a 5-1 deficit in the second set after a double-fault. Pliskova served out the biggest win of her career a game later on a second match point.
Kerber is looking forward to the US Open which begins in eight days.
"This season I won my first grand slam, everything what's happened in the last months is just incredible. I'm trying to enjoy it," she said.
"Some days you're losing matches, some days you win. I'll try to take the positive things from the match and from the last few weeks to New York," she said in reference to the upcoming US Open, the year's final Grand Slam Tournament.