Austrian second seed Dominic Thiem has advanced to the second round of the US Open as Spaniard Jaume Munar retired after dropping the first two sets.

Thiem, who reached his third grand slam final at this year’s Australian Open where he lost to Novak Djokovic, was leading 7-6(6) 6-3 when Munar ended the match.

Munar came back from 5-3 down in the opener to pull ahead but Thiem held to love to force a tiebreak which he went on to secure on his second set point when he fired down an ace.

After Munar held serve to level the second set at 3-3, Thiem stepped up his game and won 12 of the next 16 points to seize control before the Spaniard retired after one hour and 55 minutes.

Up next for Thiem will be India’s Sumit Nagal, who beat Bradley Klahn 6-1 6-3 3-6 6-1.