RIO DE JANEIRO -- Top-seeded Carlos Alcaraz advanced to the second round of the Rio Open on Wednesday, with his mind already set for a year-long contest with Novak Djokovic for the No. 1 ranking.

The 19-year-old defending champion closed out the last two games of a match suspended the previous day because of rain to complete a 6-4, 6-4 win over Mateus Alves.

Alcaraz will next play Fabio Fognini, who beat Tomas Barrios Vera 6-2, 6-3 at the clay court tournament.

The Spanish teenager was sidelined for four months with a leg muscle injury and returned to the tour last week at the Argentina Open, where he dropped only one set en route to his first title since his Grand Slam breakthrough at the U.S. Open last year.

Alcaraz, who in 2021 became the first teenage year-end No. 1 in ATP history, is currently second in the rankings. He said he doesn't feel pressure to topple Djokovic from the top but he has set that as a key goal for 2023.

"Truth is a beautiful year awaits, with beautiful tournaments. It is true there will be a little pressure to defend important titles. I will have to play at a good level but, as I always say, I play every match thinking I have to enjoy it, much beyond the results," Alcaraz told a news conference. "I have to try to win more Grand Slam titles, reclaim the No. 1 position. That's what I am hoping for this year."

The hottest up-and-coming player on tour has titles to defend in Rio, Miami, Barcelona, Madrid and in the last major of the season in New York.

Alcaraz struggled at times against Alves, a Brazilian ranked No. 556 . He needed almost two hours of play to win, saying he'd only seen videos of his 22-year-old rival before their match.

"It is not easy to stop after an entire match and have to start it again the next day," Alcaraz said. "I feel I am doing well after four months injured. I had a very good week in Argentina and I am coming here with a lot of confidence."

Also on Wednesday, second-seeded Cameron Norrie advanced with a 7-5, 7-5 win over Thiago Monteiro in 2 1/2 hours. He will face Hugo Dellien in the next round. The Bolivian beat Alex Molcan 1-6, 6-2, 6-2.

Norrie had the advantage of playing his entire round of 16 match on Wednesday while others were stopped by rain.

Last year's runner-up Diego Schwartzman was knocked out by Serbian player Dusan Lajovic 6-1, 6-4. Lajovic will next face compatriot Laslo Djere in the round of 16.

Fourth-seeded Francisco Cerundolo beat Roberto Carballes Baena 4-6, 6-3, 6-3 and will meet Bernabe Zapata Miralles in the next round.

Home crowd favorite Thomaz Bellucci had the last match of professional career against Sebastian Baez, who won 6-3, 6-2. The 35-year-old Bellucci's best ranking position was No. 21 in 2010.

Baez next rival will be Juan Pablo Varillas.