Britain's Andy Murray defeated American lucky loser Noah Rubin in the Winston-Salem Open first round after scheduled opponent Nick Kyrgios withdrew.
Former world number one Murray, 34, beat Rubin 6-2 6-0 and clinched victory by winning 10 successive games.
The three-time Grand Slam champion was due to face Australia's Kyrgios, who pulled out because of a knee injury.
Murray, who is set to compete at the US Open from 30 August, will face American Frances Tiafoe next in North Carolina.
"I didn't know if I was going to play tonight. They said if I was playing against a qualifier then I wouldn't play and then I drew a lucky loser.