Golf’s World Cup winner Jason Day is proud he didn’t buckle in the face of family tragedy or his desperation to break through in Australia.

And the 26-year-old believes his triumph at Royal Melbourne takes him a step closer to winning a major.

With his grieving mother and his sisters watching on, the 26-year-old Queenslander stood firm over the tough closing stretch at Royal Melbourne on Sunday to claim his first tournament win in more than three years, and first on home soil.

Day and Adam Scott also comfortably delivered Australia the World Cup for the first time since 1989, the duo finishing 10 shots clear of the United States.

Day’s individual victory was much tighter.

He started Sunday one shot in front of Denmark’s Thomas Bjorn and moved four clear by the halfway mark.

But a double-bogey from Day on the 10th, then two birdies in three holes from Bjorn, had them level with three holes to play.

It was the veteran Dane who faltered, bogeying the par 4 16th, while Day made a clutch par save after finding a greenside bunker.

Day clinched his win with a superb approach to the 18th, while Bjorn found the sand on the way to another bogey, ensuring a two-shot victory for the Australian.

Having regularly contended for titles, including majors, since his sole win on the US PGA Tour in 2010, Day said Sunday’s win was a crucial breakthrough.

“I finished the job, which was great, I’ve been close so many times now,” Day said.

“To have a one-shot lead going into Sunday and all that time to think about it … to win like that was a very big move in my golfing career.”

It came against the backdrop of Day learning days before the event that eight relatives had died in Typhoon Haiyan in the Philippines.

“The biggest thing right now is to know that I just didn’t give up,” he said.

“It would have been the easiest thing for me to just go ahead and pull out of the tournament.”

His win warmed the heart of his mum Dening, whose own mother was one of the victims.

“The win is the best thing that happened after the disaster in the Philippines, so I’m so happy,” she said.

Day received $1.2 million for his individual victory, plus half of the $600,000 team first prize and plans to support Philippines victims.

“We’ll definitely be giving some money or raising money and trying to raise awareness,” he said.

Day, who’s had four top-three finishes in majors, including two this year, said Sunday’s experience could help him go a step further.

“Hopefully the next time I have a chance at winning a major I play this way and hopefully the next major I play in I win.”