Kyrgios won his fifth ATP Tour title with victory at the Mexican Open
Australia's Nick Kyrgios beat world number three Alexander Zverev 6-3 6-4 to win the Mexican Open in Acapulco.
The 23-year-old started the week 72nd in the world - his lowest ranking in five years, but is expected to return to the world's top 30 after this win.
Zverev was the third top-10 player Kyrgios beat to reach the final, after victories over Rafael Nadal and John Isner and a win against Stan Wawrinka.
"I knew I was the underdog going in," he said. "I didn't expect much."
Kyrgios was handed a silver pear trophy and a black sombrero as he won his fifth ATP Tour title win.
He added: "It's an amazing feeling. He's an incredible player and doesn't have many weaknesses, so I knew I had to play my style of tennis. I'm really happy with the performance."
During the week Kyrgios has battled hostile crowds, illness, injury, cramps and after beating Nadal, was criticised by the Spaniard for "lacking respect".
"It's hopefully an example for people who are struggling and getting in some places you don't think you can get out of," said Kyrgios. "If I can do it, you can do it.
"I was really down and out and didn't know what I was going to do, but you have a week like this and things can change."
It was a straightforward victory for Kyrgios against German Zverev, after spending more than nine hours on court in his four previous matches.
Zverev said: "If you beat four players like that in an [ATP] 500 tournament, you deserve to win it. He's the real champion of this week."
The tour now moves to the US for tournaments in Indian Wells and Miami.
