Rory McIlroy recovered strongly from a faltering start to ensure Francesco Molinari's flawless six-under was only good enough for a share of the BMW PGA Championship.
McIlroy had a three-shot advantage after two days of play at Wentworth but he struggled on the front nine on Saturday, the Northern Irishman reaching the turn at two over.
The 2014 winner rallied on the back nine and finished with successive birdies for a 71 to end the day on 13 under for the tournament, with Molinari's brilliant performance meaning the pair have a four-shot cushion from the chasing pack.
Although Molinari hit his second shot at the last into the water, he successfully got up and down for par to wrap up a bogey-free round that took full advantage of favourable conditions.
Molinari, runner-up last year, showed little sign of the fireworks to come after going even-par through seven, but consecutive birdies at the end of his front nine built momentum.
And with four further gains Molinari moved above McIlroy, who posted a double-bogey on the par-four sixth when he followed a wayward drive by firing a shot into a spectator who did not appear to sustain a significant injury.
But the Northern Irishman quickly turned things around, a birdie at the next got the four-time major winner back on track.
A further gain at the 12th put McIlroy two adrift of Molinari and, despite another disappointing tee shot on the last, he made back-to-back birdies to draw level with Molinari.
Ross Fisher cannot be discounted after he matched Saturday's 68 to move to nine under, the same score as defending champion Alex Noren and Branden Grace, who continued his consistent week with a third successive 69 to stay in the hunt.