AUCKLAND, New Zealand -- Two-time champion Roberto Bautista Agut was knocked out of the ASB Classic in the first round Tuesday, beaten 6-4, 6-3 by fellow Spaniard Roberto Carballes Baena.

Bautista Agut won the Auckland title in 2016, beating John Isner and Jo-Wilfried Tsonga in early matches, and again in 2018 when he beat Juan Martin del Potro in the final.

He missed a substantial part of the 2023 season when he was injured in a horse-riding incident in July. He returned in October and reached a final at Valencia in November and the quarterfinals in Hong Kong last week.

Bautista Agut still appeared a little rusty at the start of his match Tuesday against his friend and training partner.

He dropped serve in the opening game and again to trail 4-1, appearing to be a little lethargic and lacking touch.

But he rallied when he held serve in the seventh game that went to deuce nine times, saving six break points. Carballes Baena crashed into unoccupied courtside seating as he ran to chase down a wide overhead shot from Bautista Agut late in that game.

He was stuck awkwardly for some time, doubled over a low barrier. Bautista Agut and the chair umpire raced to his assistance and he was able to resume after a short break.

Bautista Agut held serve, then broke Carballes Baena to get back into the set but Carballes Baena served out the set in the next game.

Bautista Agut broke in the second game of the second set but Carballes Baena broke back and then took a 3-2 lead.

He faced heavy pressure in his next service game, losing four consecutive points after leading 40-0. He recovered and took the game and from then on had little trouble clinching the match in 1 hour, 43 minutes.

"It's always tough playing against Robert, he's a really good friend and we practice together and it was really difficult," Carballes Baena said. "But I think I did a great match. I was really aggressive and serving really well."

Defending champion Richard Gasquet also made a first-round exit, losing 6-3, 6-4 to sixth-seeded Arthur Fils.

The loss means Gasquet will drop out of the top 100 for the first time since April 2005 when the next rankings are released. He has spent 956 consecutive weeks as a top 100 player. The ATP said the 37-year-old Gasquet needed to reach the final in Auckland to remain in the top 100.

Former No. 10-ranked Denis Shapovalov also went out in the first round in his first competitive match back since a fourth-round loss at Wimbledon in July due to a serious knee injury.

He lost 6-4, 6-2 to in-form Austrian Sebastian Ofner, who reached the semifinals in Hong Kong last week.

The Canadian was due to play qualifying in Auckland but received a wild card.

Shapovalov appeared confident on his knee but wasn't at full stretch. He still timed and hit the ball well but dropped service games early in both sets.

"He was still a bit struggling which was good for me but it's good to see him back and healthy," Ofner said.