Nadal was taken to a tie-break in both sets but emerged victorious at the Indian Wells Tennis Garden in California in the United States to extend his perfect start to the Association of Tennis Professionals Tour season to 18 matches.

The 21-time Grand Slam champion edged the opening set before coming from a break down to win the second, completing a 7-6, 7-6 triumph.

It has been a sensational start to 2022 for Nadal who bounced back from a injury-hit 2021 to win three successive tournaments, including the Australian Open.

However, Nadal revealed he experienced issues with the foot that troubled him last season during his match with Opelka.

"I felt my foot a little bit in the second set," said Nadal.

"I was able to keep going, keep running until the end, no?

"I am just very happy to be playing tennis.

"Today was a little bit worse than other days.

"It’s true that the last couple of days the foot has been bothering me a little bit more.

"Something that can happen.

"Just try to be ready and start positive because [it’s] going to be my last tournament on hard.

"After we [are] going to go back on clay.

"That probably helps a little bit more."

Nadal is next due to face Kyrgios who advanced to the last eight after Italy’s Jannik Sinner withdrew due to illness.

The pair have been involved in some memorable clashes, with Nadal leading the head-to-head 5-3.

Spanish teenager Carlos Alcaraz secured his place in his first ATP Masters 1000 quarter-final with a 7-5, 6-1 win over Frenchman Gaël Monfils.

The 18-year-old will now tackle Britain’s Cameron Norrie who continued his defence of the Indian Wells title with an impressive 6-2, 6-4 triumph against American Jenson Brooksby.

The biggest shock of the day saw Serbia’s Miomir Kecmanović stun world number six Matteo Berrettini of Italy 6-3, 6-7, 6-4.

Kecmanović, who is ranked number 61 in the world, will hope to continue his run as he meets American Taylor Fritz next.

Fritz downed Australia’s Alex de Minaur 3-6, 6-4, 7-6 to move through to the last eight.

Romania’s Simona Halep and Poland’s Iga Świątek were comprehensive winners in the quarter-finals of the women’s singles.

The pair lost just three games between them, with third seed Świątek thrashing Madison Keys of the US 6-1, 6-0 and Halep seeing off Petra Martić of Croatia 6-1, 6-1.

It will be the third meeting between the two players and first outside the Grand Slams with Halep holding the edge in the rivalry after wins at the French Open and Australian Open.

The other two quarter-finals are set to be held tomorrow with defending champion Paula Badosa of Spain taking on Russian Veronika Kudermetova, competing as a neutral, and sixth seed Maria Sakkari of Greece going up against Elena Rybakina of Kazakhstan.