Garth Mulroy and Gonzalo Fernandez-Castaño reached the turn in a share of the lead but the BMW Italian Open presented by CartaSi looked to be wide open midway through the third round.
South African Mulroy carded an outward 33 with four birdies and one bogey to reach 14 under par at Royal Park I Roveri, and Fernandez-Castaño’s bogey at the ninth ensured that was good enough for a share of top spot.
The Spaniard had produced three birdies, one bogey and an eagle at the long eighth prior to that, however, and was also three under for his round through nine holes.
They were one ahead of four players including clubhouse leaders Matteo Manassero and Nicolas Colsaerts. The Italian teenager and Ryder Cup-bound Belgian both signed for impressive 65s, and were joined by Rafa Cabrera-Bello - five under with three to play - and Grégory Bourdy, the Frenchman reaching two under after eight holes.
A further seven players were clustered on ten under, and while another member of Europe’s Team heading to Medinah in a fortnight was going well on nine under in the shape of German Martin Kaymer.
"I'm very pleased,” said Colsaerts, who will win his debut Cap against the Americans in Chicago.
“I played well all day and it felt like I was very chilled out on the course.
"It's almost like my mind's already somewhere else and I can just play freely. I was just trying to squeeze every shot until the end there, because I won't be leading tonight and I wanted to get as close as possible.
"Regardless of what happens tomorrow, my goal is to get to The Ryder Cup as prepared as I can be and be in this great frame of mind that I'm in now. I'm doing all the right things.
"On a day like today when everything goes your way it's easy to stay relaxed. But my mission is to stay focused on what I needed to do today and take it shot by shot. I had a little hiccup on the 16th, but it was nice to finish with a birdie."
