World number two Novak Djokovic said Andre Agassi will be his new coach after the Serb lost in the Italian Open final to Alexander Zverev.
The 12-time Grand Slam winner parted company with his entire coaching team earlier in May.
Former world number one Agassi will be with Djokovic in Paris for the French Open, which starts on 28 May.
The news was confirmed after German Zverev, 20, stunned Djokovic 6-4 6-3 to win in Rome.
In the women’s event, Ukraine’s Elina Svitolina triumphed with a 4-6 7-5 6-1 win over Romania’s Simona Halep.
At 20 years and one month, Zverev is the youngest Masters event champion since Djokovic himself won the 2007 Miami Open.
Fearless Zverev, currently ranked 17 in the world but now set to move into the top 10, dominated from the start.
He did not face a break point and broke the 12-time major winner in the first game and twice in the second set.
Djokovic received a code violation for an audible obscenity in the seventh game of the second set, and later double-faulted to hand Zverev match point.
A long backhand by the Serb, who will celebrate his 30th birthday on Monday, subsequently ensured victory to his highly-rated opponent.
Djokovic’s semi-final win over Dominic Thiem had hinted he was close to recovering his best form after a poor year, culminating in the departure of his entire coaching staff earlier this month.
But Zverev was composed throughout and won in one hour and 21 minutes.
“It’s such an honour being on the court against one of the best ever players,” said Zverev after his victory.
“If I have half the career Novak has had, I will be just fine.”
Referring to the French Open, the second Grand Slam of the year, which begins on 28 May, he added: “I’m sure he will be one of the favourites in Paris.”
Djokovic will need to raise his game having hit 27 unforced errors to his opponent’s 14, but hinted at a big future for the German.
“You are definitely on a great path. You played fantastic and deserve it,” he said.
Svitolina fought back from losing the first set to win her fourth title of the year.
The 22-year-old is currently ranked 11th in the world, but will return to the top 10 when the rankings are updated on Monday.
Halep, 25, who won the Madrid Open last week, rolled her ankle when leading 5-2 in the first set, but managed to take it 6-4.
The world number four had her ankle strapped in the second set, which Svitolina took 7-5.
The third set was a one-sided affair as Svitolina won 6-1 in 30 minutes.
Svitolina, who also called for a trainer in the second set, adds her Rome title to victories in Istanbul, Dubai and Taipei City.