Nick Kyrgios defeats Alexander Zverev in straight sets in Mexican Open final

Nick Kyrgios has earned himself half-a-million dollars, a handy rankings boost and a sombrero for crowning a glorious week in Acapulco with the fifth ATP title of his career.

The enigmatic Australian brought world No.3 Alexander Zverev crashing back to earth with an emphatic 6-3 6-4 victory over the German in Sunday's Mexican Open final.

Top-seeded Zverev hadn't dropped a set en route to the final, but couldn't win any against Kyrgios, who will regain his place in the world's top 50 after hoisting his first trophy in almost 14 months.

Zverev is Kyrgios's fourth big scalp in six days after he had also recorded wins over Rafael Nadal, Stan Wawrinka and John Isner to make the title match.

"Well done to Nick - he beat three top-10 players and Stan, who's a grand slam champion. So to beat four players like that in a 500 (series) event, you deserve to be the champion," said a gracious Zverev.

"He's the one who deserves to win the tournament this week."

The two combatants had split their previous six encounters but, clashing for the first time in a final, Kyrgios broke Zverev early in both sets.

After pocketing the opening set, and breaking Zverev in the first game of the second, Kyrgios briefly lost focus to gift the German a foothold in the match.

From 30-love up, Kyrgios berated himself for double-faulting on break point down as Zverev looked to be assuming momentum.

Zverev conjured two more break points with Kyrgios serving at 1-2 but, after surviving, Kyrgios continued to frustrate Zverev with a series of well-disguised drop shots from the back of the court.

In breaking Zverev from 40-love up, Kyrgios also broke the second seed's spirit as he forged ahead 4-2.

There was no way back as Kyrgios sealed victory in one hour and 30 minutes, ensuring a rise from No.72 to 43rd in Monday's rankings, not to be mention a $US367,630 ($A519,000) cheque, a unique trophy and even a sombrero.

"This is an amazing tournament. I loved it two years ago and have some crazy memories here," said Kyrgios, who also scored his first win over world No.1 Novak Djokovic in 2017 in Acapulco.

Meanwhile, Kyrgios's countryman Alex de Minaur, who succumbed to Zverev in the quarter-finals, will climb to a career-high No.23 in the world after his run in Mexico.