(Adds Zverev quotes)
MELBOURNE, Feb 8 (Reuters) - Sixth seed Alexander Zverev overcame an inconsistent start to battle past unheralded American Marcos Giron 6-7(8) 7-6(5) 6-3 6-2 in the opening round of the Australian Open on Monday.
After losing a first-set tiebreak, Zverev went up an early break in the second and was serving for the set at 5-3 when Giron broke him, prompting the German player to smash his racket in frustration and pick up a code violation in the process.
However, he clung on to win the set in another tiebreak to level the match, and got another early break in the third to take control as his serve finally began to fire.
Zverev, who is bidding for a first Grand Slam title, advanced to the second round without offering world number 75 Giron a break point opportunity in the final two sets, sealing victory with a trademark backhand down the line.
"He played incredible I think," Zverev said of Giron, who was making his main draw debut in Melbourne.
"He knew to be on this stage against a top-10 player he needs to come out firing.
"He had me on the ropes there, especially in the second set. It could have gone either way... I'm happy to get through and in the end I started playing better.
"The first round of a Slam is never easy... my body was a little bit fatigued, but this is a Slam, you don't have easy opponents. Sometimes it just what you have to do, you've just got to win the matches."
Zverev will next play either Taro Daniel or Maxime Cressy.