AUCKLAND, Australia (AFP) — Top seed Ben Shelton got his Australian Open preparations back on track Wednesday after a run of defeats with a 6-4, 6-3 win over Hungary's Fabian Marozsan in the Auckland Classic.

The American world No. 16 reached the quarter-final of the Australian Open, the last four at the US Open and secured a first ATP title in Tokyo in his first full season on tour in 2023.

But the 21-year-old ended his campaign with first-round exits in Vienna and Paris, before another first-up loss last week in Brisbane.

"It was definitely a tough match playing against Fabian," said Shelton, who had received a first-round bye, after getting past the world No. 65 in 71 minutes.

"I had a tough win against him last year at a Challenger tournament. So really cool to have a match-up first against him, he's a great player. It was a fun match but happy to get through it."

Shelton, who sent down 10 aces, faces a quarter-final on Thursday against Spaniard Roberto Carballes Baena, who beat Austrian seventh seed Sebastian Ofner 7-5, 6-3, one of several seeds to tumble out on Wednesday.

Third-seed Francisco Cerundolo of Argentina was thrashed 6-1, 6-1 by France's Alexandre Muller and eighth-seeded Australian Max Purcell lost 6-2, 6-4 to Japan's Taro Daniel.

Fourth seed Felix Auger-Aliassime of Canada lost his first singles match of the year 7-6 (11/9), 7-5 to German Daniel Altmaier.

The former US Open semi-finalist was coming off just one mixed doubles appearance for Canada at the United Cup teams event in Sydney last week, where he did not play singles because of knee pain.