Caroline Wozniacki thought “this can’t be real” as she finally won her first Grand Slam title Saturday and regained world number one status for the first time in six years.

Wozniacki threw her racquet in the air and collapsed to the ground in tears after battling Simona Halep found the net on match point in the Australian Open final.

“On that match point I thought this can’t be real. It wasn’t just being Australian Open champion, it was Grand Slam champion and world No 1,” said the Dane after finally triumphing in her 43rd Grand Slam tournament.

“There’s a lot going through your mind at that point. You’re like, ‘No, I had an opportunity.’

“I should have hit it a little bit differently. When I saw that ball go into the net, it was crazy emotional.”

It was the climax of a thrilling 7-6 (7/2), 3-6, 6-4 win against the tough Romanian top seed after 2hr 49min of a gruelling encounter played in high heat and humidity on Rod Laver Arena.

“It was such a tough grind. It was very hot out there. I think both of us were very tired in the end,” said Wozniacki, 27, who recorded her fifth – and most important – victory against Halep in seven career meetings.

The Dane also set a new record for the longest gap between stints at the top since computerised rankings were introduced in 1975, eclipsing Serena Williams’s record of five years and 29 days.

“Obviously that’s very special. I think being new Grand Slam champion and world No 1 sounds pretty good,” said Wozniacki. “I’m very excited for that. It’s a dream come true.”

‘I’m exhausted’

Both players needed medical attention during the brutal encounter in energy-sapping conditions so hot there was a 10-minute “extreme heat” break between second and third sets.

“I was thinking, If I am tired right now... I know she’s tired, too,” said Wozniacki.

“Every time I was like, ‘Oh, I can’t do this anymore, I’m exhausted.’

“And we were playing all these crazy long rallies, I was thinking, ‘OK, I’m looking over there, she looks a little tired, she must be feeling the exact same way or maybe more tired than me’.”

It was a relief, she said, to talk to reporters and not be asked when she was going to win a Grand Slam. Wozniacki previously lost finals in New York in 2009 and 2014.

“Honestly, I think that’s one of the most positive things about all of this. I’m never going to get that question again,” she said with the trophy proudly by her side.

“Regardless, I think I’ve had an incredible career. The end of the day, I think a lot of people would like to be in my position. Nobody knows how much work, dedication you put into it.

“I’m just waiting for the question, ‘When are you going to win the second one?’” she said, laughing.

“Right now I’m just happy I have this one, and I’m going to really enjoy this moment.”