It's definitely Jason's day!

Australian golfer Jason Day got a taste of his first major tournament win on Sunday when he bagged the 2015 PGA Championship at Whistling Straits from Jordan Spieth.

It was a record-breaking final score for Day who earned a 20 under par, which according to BBC, broke Tiger Woods' record of 19 under during the 2000 Open Championship.

The 27-year-old golfer reportedly started off the final day in the championship with a two-stroke lead.

He had a mishit during the 9th but he was able to recover during the 11th and 14th.

BBC said he earned a seventh birdie on Sunday and "played the treacherous closing two holes superbly."

Day, in an interview after the championship, said that he did not think he would have been emotional with his win.

"I didn't expect I was going to cry. A lot of emotion has come out just because I've been close so many times and fallen short. To be able to play the way I did today in tough conditions with Jordan in the group - he was the favourite - to be able to play the way I did was amazing," Day told BBC.

He added that he was really happy with the way he played and that he could not ask for anything better than his performance.

According to USA Today, Day attributed his victory to his failures in the past.

"The experiences that I've had in the past with previous major finishes has definitely helped me prepare myself for a moment like this. I was one of those guys where I was so close and I wasn't the last man standing and it was frustrating for me," added the golfer.

He also said that he was patient with himself and he remained disciplined whenever opportunities were given to him.

Yahoo Sports reported that Day seemed to have taken his failures on a positive note, learning from them and making these his inspiration to succeed.

"The biggest thing that prepares you for something like this is just the sheer experience of failure. Looking at failure not as a negative but as a positive. Knowing that you can learn from anything, even if it's bad or good. And that really gets you mentally tough," he said.

As for Spieth, he reportedly accepted his loss with a humble heart. "There is nothing I could have done," he said as he turned to Day.

Considered the best player in the tournament, Spieth did not seem to had the right formula in going against Day but he still remained on top of new world rankings.

"It's as good a consolation prize as I've ever had. It was not easy to dethrone Rory and it's going to be even harder to try and stay on top," he added.