Andy Murray
Murray defeated Llodra in straight sets after rain delay at US Open. (Reuters)

Andy Murray got the defence of his US Open title off to a successful start with a 6-2 6-4 6-3 victory over Michael Llodra of France on Wednesday night.

A four hour rain delay saw the third seed's opener postponed until 10pm local time in New York but a straight sets victory saw him seal his place in the second round of the tournament in just over an hour and a half, moving on to face Leonardo Mayer of Argentina on Friday.

Murray broke Llodra in the first and seventh games of the first set but fell 0-3 behind in the second as Llodra took a swift lead. However the Scot proceeded to win five games back to back to take back the initiative, before sealing a comfortable victory with a 6-3 win in the third at the Arthur Ashe Stadium.

Murray's contest was the third latest start for the night session on Wednesday, with critics suggesting the defending champions' schedule may leave him at a disadvantage later on in the tournament.

"It's nothing to do with me being defending champion, there were quite a few matches (still going on Wednesday evening)," Murray said, speaking to BBC Radio 5 live.

"Anyone that knows sport knows that playing seven matches over 13 days is harder than playing seven matches over 15 days.

"You obviously get less time to recover and rest, but you deal with it, do all the recovery stuff and get as much sleep as possible. Now I'm in a routine of playing every other day, which you do at all the other Slams."

Elsewhere, Juan Martin del Potro saw his contest with 74th ranked Guillermo Garcia-Lopez also delayed by rain, before rallying to defeat his opponent in a gruelling four-set win 6-3, 6-7 (5), 6-4, 7-6 (7) that lasted over four hours.

"I think of all of the matches of the first round, I have the toughest one," the Argentine said following his win.

"We play every time long rallies. I got to make three or four winners in the same point to win the point."