Thiago Monteiro enjoyed a memorable victory on Monday as he defeated former world number three Dominic Thiem 6-1 3-6 7-6 (7-2) in his opening match of the Rio Open.

The highest-ranked Brazilian in the field made a winning start at South America's only ATP 500 event, but he had to work for it, emerging victorious after an 88-minute third set.

A raucous crowd cheered on every point down the stretch, and after saving four break point opportunities to force a tiebreaker, he jumped ahead to a 5-1 advantage and served it out.

He will face the winner between second seed Cameron Norrie and rising Argentine talent Juan Manuel Cerundolo in the next round.

Meanwhile, the top seed in action on Monday – third seed Lorenzo Musetti – continued his recent rough stretch of form with a disappointing 6-4 6-1 defeat at the hands of Chile's Nicolas Jarry.

Musetti, already ranked 18th in the world at 20 years old, has now lost four of his past five matches, while Jarry has won eight out of 10.

Jarry will play Spain's Pedro Martinez in the second round after he spoiled a potential all-Chilean matchup, eliminating Cristian Garin 7-6 (7-0) 6-4.

The only other Brazilian in action, Joao Fonseca, had no luck against Slovakia's Alex Molcan as he went down 6-0 6-3, while Bolivia's Hugo Dellien was similarly dominant in his 6-0 6-2 trouncing of Portugal's Joao Sousa.

After taking a set off world number two Carlos Alcaraz at last week's Argentina Open, Laslo Djere advanced into the second round as Facundo Bagnis retired in the second set while trailing 6-2 3-2.