Winston-Salem, United States, 20 August 2019 | AAP

Australian Alexei Popyrin advanced to the second round of the ATP Tour’s Winston-Salem Open after a three-set win over Brazilian Thiago Monteiro in a rain-interrupted clash.

The 20-year-old world No.106 had his nose in front of Monteiro before play was suspended for about five hours due to heavy rain.

But Popyrin, who blasted 16 aces and converted his single break point, held his nerve in the third set tiebreaker to win 5-7 6-4 7-6(7).

The result sees him advance to a meeting with 13th-seeded Serbian Miomir Kecmanovic.

Australian 14th seed John Millman received a first-round bye and on Tuesday (local time) will face Italian Marco Cecchinato, who advanced to the second round when Alexander Bublik retired in their opening match.