Mikko Ilonen turned in a sparkling 9-under 63 Friday and grabbed a three-stroke lead at the China Open.
Ilonen, a two-time European Tour winner, sits at 12-under 132 through 36 holes, three strokes clear of Brett Rumford and Kiradech Aphibarnrat.
"I've had a couple of other 63s on the tour before, but it's difficult to compare," said Ilonen. "For example, I may have played better and only shot a 69. I've probably struck the ball better this year, but I don't think I've putted better. It's a good number of birdies definitely -- I felt really good with my putter."
Rumford, last week's Ballantine's Championship winner, and Aphibarnrat, who won his first European Tour title at the Maybank Malaysian Open in March, both carded 67s at Binhai Lake Golf Club and retained a share of second place.
Overnight leader Robert-Jan Derksen slid into fourth place at 8-under-par with a second-round 70. He hasn't won on the European Tour since 2005 and hasn't had a top-10 finish on the circuit in over two years.
Pablo Larrazabal (66) and Lee Slattery (68) share fifth place at 7-under, while Graeme Storm (68) and Matthew Griffin (68) are knotted in seventh at minus-6.
Defending champion Branden Grace bounced back from a slow start and moved to 3-under through 36 holes. The world No. 32 was 5-over late Thursday before picking up birdies on three of his final five opening-round holes. He maintained the momentum a day later with a 5-under 67.
Amateur Wo-cheng Ye of China made history when he teed off Thursday as the youngest player to compete in a European Tour event at 12 years and 242 days old. He failed to make the cut, however, carding consecutive 79s and finishing at 14-over.
Rumford began his second round on the 10th tee and countered two bogeys against seven birdies, including four straight starting at the par-5 sixth, to hit the clubhouse with the lead.
"It's a nice feeling when you're holing putts and seeing your name up near the top of the leaderboard," he said. "You've got to make the most of these moments when they come along, and I'm managing to do that at the minute."
Aphibarnrat had just one bogey during his round and claimed a share of the lead with a gain at the par-4 15th, one of his six birdies on the day. He parred out to stay at 9-under.
Six years removed from his only two European Tour victories, Ilonen went out with the later wave and methodically seized control of the top spot.
The Finn began his day with a birdie on the 10th and recorded an outward 33 thanks to consecutive gains starting at the 15th. He surged around the turn, carding birdies on Nos. 1 and 2 before dropping his approach on the fifth within three feet and tapping in for birdie and a share of the lead.
Ilonen grabbed sole possession of the top spot with another birdie on the sixth, and followed a par on No. 7 with back-to-back birdies to move three strokes clear.
"I hit the ball better than yesterday," said Ilonen, who finished ninth in Qatar and second in Morocco this season. "I gave myself a few more chances on the greens, especially on the back nine, and managed to take quite a few of them, so it was a very stress-free round today. I didn't put myself in any trouble at all, which is always nice, and it's nice to be three ahead going into the weekend."
NOTES: Ilonen's European Tour wins came at the Scandinavian Masters and Indonesia Open, both in 2007 ... Derksen's last win on the European Tour was at the 2005 Madeira Island Open. His only other win on the circuit came at the 2003 Dubai Desert Classic ... Grace finished tied for 18th at the Masters three weeks ago. He has three top-10 finishes on the European Tour this season after recording four wins in 2012 ... Ye qualified for this tournament by finishing in the top three in the Western China Qualifying. He broke the record held by Tianlang Guan, who was 13 years and 177 days old in this event in 2012. Guan went on to become the youngest player to compete and make the cut at the Masters this year.