A stunning eagle from Australia’s Jason Day has helped him to a four-shot lead during the last round of golf’s World Cup at Royal Melbourne.

It’s also given Australia a commanding eight-shot lead over the United States in the teams competition.

Day started the day on nine under par, one shot ahead of his playing partner, Denmark’s Thomas Bjorn.

He had a bogey and two birdies on his first four holes to move to 10 under and two shots clear of Bjorn.

Bjorn briefly joined him in the lead with a birdie on the par 3 fifth, which Day bogeyed after finding a bunker.

But the Australian responded superbly on the par 4 sixth, holing a short approach, which landed in the cup on the first bounce for an eagle to take him to 11 under par.

Day, seeking his first professional win on home soil, threw his hands up in celebration.

Bjorn bogeyed the same hole to sink to eight under, giving Day his three-shot buffer.

Bjorn then added another bogey on the seventh to fall four shots off the pace.

Australian Adam Scott was in third place on six under par.

Scott, who began the day at two under, started his round spectacularly, holing his approach on the first for an eagle then following that with two birdies.

His next six holes included a bogey and a birdie.

The Australians’ combined total of 17 under put them well clear of the US (nine under) after they started Sunday just one ahead of the Americans.

If they go on to win, it will be Australia’s first World Cup victory since 1989.