It looked like Danny Willett would take a clear lead into Saturday, but his five-shot gap disintegrated as Scott Hend and Y.E. Yang pounced.
Danny Willett joined Scott Hend and Y.E. Yang at the top of the BMW PGA Championship leaderboard despite a day of mixed fortunes.
A brilliant front nine from the Masters champion saw him hit the turn six-under par for the round, setting a new tournament record.
Willett's excellent opening sent him five shots clear, but, after dropping a shot at the 10th, he produced a hat-trick of bogies from 15 to 17.
A birdie on the final hole sent him back to minus 10 for the tournament, which proved enough to keep Willett content.
"I played great most of the day and then chucked a couple of horrid shots in there and it was nice to make birdie at the last after composing myself quite nicely," said Willett.
"It was still not quite the back nine I was hoping for, but, 10-under par, you'd have taken it at the beginning of the day."
But by the close Willett was joined at the summit by two of the joint overnight leaders.
Hend had fallen away with two bogies in succession on 15 and 16, but an eagle on the par-five 18th sent him level with Willett.
Yang also produced a moment of magic on the final hole to keep pace, escaping from the bunker befre holing for birdie to seal a three-way tie.
Jaco van Zyl is a shot back in fourth, while Jorge Campillo surged up 28 places to fifth by carding 67.
Joost Luiten, one of the three overnight leaders, made five bogies in a two-over round that sent him down to tied sixth.