HONG KONG (AFP) - A battling performance from an under-the-weather Rory McIlroy saw him sharing the lead with Alvaro Quiros after the second round of the $2.75 million UBS Hong Kong Open on Friday. The world number two was left to rue a bogey on the par-five last at the Hong Kong Golf Club as he ended play with a one-under 69, for a two-round seven-under par total, level with Quiros of Spain who shot the same score earlier in the day. "Obviously it wasn't the way I wanted to finish," said the 22-year-old from Northern Ireland. "I hit a few loose shots coming in. It's something I'll have to try and eliminate tomorrow if I want to try and lead this golf tournament going in to Sunday. "I feel like I definitely could have shot a few better today. But you know, if that's my worst round of the week, it's not too bad." McIlroy revealed after his round that he has also been struggling with his health this week, after spending three days on a saline drip during a recent holiday to the Maldives with his tennis playing girlfriend Caroline Wozniacki, the world number one. "I got sick for a few days so that sort of took a little bit of energy out of me," said McIlroy. "I think that is sort of a little bit still there. I mean my energy levels. It's the end of the season. I'm sure it's not just me that's feeling like this. I'm sure a lot of the guys are. It's been a long season and there's a couple of more weeks left before we get to enjoy Christmas."