Alvaro Quiros held the clubhouse lead on seven under par midway through the second round at the UBS Hong Kong Open but Rory McIlroy had the Spaniard in his sights.
Quiros carded a 69 at Hong Kong Golf Club that featured four birdies and three bogeys, including a disappointing five at the ninth, his final hole, to head the field by one from McIlroy, who birdied the third but then gave the shot back at the fourth.
"Unfortunately, I didn't play as well as yesterday," said Quiros, who shot an opening six under 64.
"I managed the round well until the first hole, my tenth. I three-putted there, I three-putted the second and after that, I didn't hole any good putts. Finishing with a bogey at the ninth was a bit frustrating but this is how it is.
"It's a shame of a round because without the two three-putts it was a proper number, nine under would be great.
"The most important thing is this afternoon, people are going to shoot low but anyway, I'm going to be up there."
Panupol Pittayarat was also at six under par after the Thai returned a 65 containing an eagle and three birdies while Miguel Angel Jiménez stood fourth, a shot further back following an even-par 70 for the Spaniard.
David Horsey was part of the group at four under par after signing for a 72 that included two birdies, two bogeys and a costly double-bogey six at the ninth, where he found the water.
"It was not as good as yesterday obviously. I played all right, iron play was good but I didn't hit many fairways, and if you miss the fairways it's difficult to control your second shot," Horsey said.
"I scrambled pretty well, didn't putt so well but it's not too bad, it's not going to be far away by the end of the day so hopefully I'll go well at the weekend."
A bogey at the sixth came after Horsey hit a beautiful second shot to three feet but ended up making a five.
"That was a bit of a shame, three-putted from three feet, it was a tough putt but I hit it too hard and the wrong line," said the 26 year old, who has two European Tour titles to his name.
"There were a few disappointments but hopefully that's my bad round out of the way and I can press on tomorrow."
Gareth Maybin, meanwhile, produced a hole-in-one at the fourth as the Northern Irishman ended one under following a 73.
"I had 199 yards, a downwind and it was a perfect number for my five iron," he said.
"It landed about ten yards short and rolled up, went in. I saw it all the way and went a bit crazy on the tee."