Jason Day’s US Open dreams are still alive despite the fact the Australian is clearly battling the effects of vertigo midway through the third round.

Day is one-over through 10 holes to drop back to one-under-par for the championship but remains in the mix as the entire field battles the extreme test of golf at a dry and dusty Chambers Bay.

Masters champion Jordan Spieth (six holes) leads the way at six-under par while fellow

American Dustin Johnson (six holes) and South African Branden Grace (six holes) are one back at five under for the championship.

Irishman Shane Lowry (10 holes) and American Patrick Reed (six holes) share fourth at three under.

Less than 24 hours after he collapsed to the ground on the final hole of his second round Day stepped up on the first tee clearly still not 100 per cent.

The 27-year-old is noticeably trying to keep his head level and guard against obvious fatigue.

But the brave warrior refuses to wilt.

Although his opening hole birdie try from 20-feet missed Day was given a huge standing ovation by the grandstand off the first green, a sign of things to come as the masses rallied around.

A three putt bogey on the second and another dropped shot after failing to get up and down from the sand on the fourth could have easily sent the Australian looking for the exit door but he knuckled down with five straight pars.

A precision approach to four feet on the 10th put him back under par for the week and right in the mix in a tie for seventh.

Diagnosed with benign positional vertigo yesterday afternoon is looking to break his major championship drought.

He has seven top 10 finishes in major championships, including three runner-ups, a third and a fourth.

Day has been suffering from fatigue and dizzy spells for the better part of a year, withdrawing from last year’s World Golf Championship Bridgestone Invitational after a similar bout of vertigo, with his issues continuing into 2015.

Day also withdrew from the Byron Nelson Championship three weeks ago before it began after struggling with dizzy spells in the Pro-am.