Queensland sprinter Buffering completed a hat-trick of Group One wins in the most desperate of circumstances at Ascot on Saturday.

Winner of the Manikato Stakes and the VRC Sprint Classic during the Melbourne spring carnival, Buffering added the $500,000 Winterbottom Stakes to his haul.

But he had to work hard for it with Victorian sprinter Moment Of Change giving Buffering a serious fright.

When Buffering, the $2 favourite, saw off the challenge from Perth star and last year's winner Barakey, he looked set for a comfortable win.

And even when Moment Of Change gave chase it appeared he was only a remote chance of getting near Buffering.

But with Buffering starting to tire under Damian Browne and Moment Of Change ($7) lifting for Luke Nolen, the result went right down to the wire with only a nose separating the pair.

Waterman's Bay, an outsider at $41, took third, just ahead of the luckless Spirit Of Boom.

Spirit Of Boom was knocked down in an incident at the 600m and lost ground before picking himself up to be in the finish for the minor placing.

Barakey, who kept Buffering off the rail for the first 600m before taking a trail, only threatened momentarily on the inside before dropping out from the 200m.