Australian Open top seed Rafael Nadal entered his third decade as a professional ranked No. 1 in the world and the 33-year-old Spaniard says he is surprised to be at the summit of the men’s game given his long and varied history of injuries.

Enjoying a rare period of full fitness, Nadal is bidding for his second title in his 15th appearance at Melbourne Park, as well as the added carrot of matching Roger Federer’s all-time record of 20 Grand Slam titles. He now has a chance to hold three out of the four Grand Slam titles after winning the French and US Opens last year.

“Well, I can’t say I have been lucky with injuries, because I have not,” Nadal — who won the Australian Open in 2009 — told reporters at Melbourne Park on Saturday. “But there is no secret. There is only passion, about love for the game, and about being able to stay positive in the tough moments.

“It’s true that I went through some tough situations during all my career. But I was able to always, with probably the positive attitude and with the right people around, to find a way to keep going.

“(It’s) something that is difficult to imagine for me because of my style of game... But here we are. Even for me is a big surprise to be where I am at my age.”

Nadal, the only player to claim the world No. 1 spot in three decades, plays unseeded Bolivian Hugo Dellien in the first round on Tuesday.

Lucky Prajnesh: Prajnesh Gunnewaran on Saturday sneaked into the men’s singles main draw as a lucky loser and may run into Novak Djokovic if he clears the first hurdle. The Indian left-hander had lost the final qualifying round to Latvia’s Ernests Gulbis in straight sets but was fortunate to make the main draw as one of the direct entrants withdrew.