Rafael Nadal reflected on a "special" day after returning to world No. 1 in the ATP men's singles rankings for the first time since July 2014. He knocked Britain's No. 1 Andy Murray off the top spot.
In 2017, Nadal has claimed a record 10th title at Roland Garros and reached the final of the Australian Open, where he lost to Roger Federer in five sets.
"Hello guys, just want to say thank you very much to all of you for your support," Nadal said in a video posted on his Instagram account.
"It has been a very good year, and today is a special one. Going back to number one, I'm just very happy."
Nadal has broken records on the ATP Tour this year -- winning the Masters 1000 title in Monte Carlo for the 29th time -- the most wins by any player at a single tournament in the Open era.
The Spaniard also claimed wins this year at the Madrid Open, where he tied Novak Djokovic's Masters record of 30 career titles, and at the Barcelona Open, where he won his 10th crown.
Most recently knocked out of the Cincinnati Masters quarterfinals by Nick Kyrgios, Nadal prepares for the next Grand Slam of the summer at the US Open, which gets underway on Monday.
"Many thanks for everything," Nadal said. "See you soon, I am practicing hard and hope to be ready for the tournament."