* Leg injury hampers Argentine in heavy defeat
* Monaco expects to be fit again within weeks (Adds Monaco quotes)
MELBOURNE, Jan 14 (Reuters) - Argentine Juan Monaco was the first seed to be knocked out of the Australian Open on Monday, succumbing as much to injury as to Russian Andrey Kuznetsov in a 7-6 6-1 6-1 first round defeat.
With all the seeds safely through to the second round as the shadows lengthened over show court two, the 28-year-old took lengthy injury time outs for treatment in a desperate bid to keep the record intact.
The 11th seed was clearly struggling, however, and howled in frustration as the 21-year-old Kuznetsov took advantage of his opponent's restricted mobility to move to the brink of victory.
Monaco, who pulled out of the Kooyong Classic warm-up last week with a hand injury, won applause from the crowd for his spirit in not retiring.
"My leg tightened up at the start of the second set and it was very tough for me," he told Reuters, gesturing to his upper right leg.
"It was always going to be tough for me to play here," he added. "But once you get out on court, you try your best. It was just too tough for me to play with two problems."
World number 79 Kuznetsov sealed the victory with his sixth ace of the match and will meet South African Kevin Anderson or Paolo Lorenzi of Italy in the second round.
Monaco reached a career high world number 10 last season after winning four tournaments and said he was confident he would be fit to play again in the next couple of weeks.
"I have to look forward," he said. "The South American swing is coming soon and that's on clay, which I love.
"In 10 to 15 days, I'm going to be ready for sure." (Editing by John O'Brien)