Nick Kyrgios held on to beat fellow Australian John Millman in three sets at the Delray Beach Open, while the Rio Open was halted by rain.
Kyrgios outlasted fifth seed Millman 6-4 6-7 (1-7) 7-6 (7-3) in the opening round of the ATP 250 tournament on Monday.
Former world number 13 Kyrgios hit 19 aces and won 85 per cent of his first serves against last year's US Open quarter-finalist, while he converted the only break point he earned.
"My serve keeps bailing me out of these types of matches, which is pretty fortunate for me," said Kyrgios. "I knew it wasn't going to be easy. John is one of the toughest competitors on tour and he's a good mate of mine, so I'm just happy to get through with the win."
Next up for Kyrgios is either 2015 champion Ivo Karlovic or Radu Albot.
Lukas Lacko defeated qualifier Yosuke Watanuki 6-4 6-4, wildcard Lloyd Harris saw off Darian King 7-6 (7-1) 6-3 and Denis Istomin beat Feliciano Lopez 7-6 (7-5) 6-2.
Meanwhile, Monday's matches were washed out at the ATP 500 Rio Open in Brazil, where all seven scheduled singles fixtures were cancelled due to rain.
Only two matches made it on court – Federico Delbonis was leading seventh seed Malek Jaziri 5-3 and eighth seed Nicolas Jarry was trailing Roberto Carballes Baena 4-3.