© Getty Images Enlarge Rory McIlroy is one shot clear at the US PGA Championship

Rory McIlroy believes his break-up with fiancé Caroline Wozniacki is the reason behind his recent run of good form as he looks to extend his advantage at the US PGA Championship.

The Northern Irishman holds a one-shot lead over Jason Day and Jim Furyk heading into the third round at Valhalla and remains on course to lift back-to-back majors having won The Open last month.

McIlroy split with former tennis world No.1 Wozniacki on the eve of the BMW PGA Championship in May but went on to triumph at the European Tour's flagship event.

Since ending his relationship with Wozniacki, McIlroy has also won The Open and the WGC-Bridgestone Invitational and has returned to the top of the rankings, and he says his event-winning form is down to breaking up with the Dane.

"I think what happened has been for the better in terms of my golf," McIlroy replied when asked about what has been the catalyst for the transformation.

"I've put a bit more time into it and it has refocused me. I mean, what else do I have to do now?

"I go to the golf course, I go to the gym and it's just my life at the minute.

"I worked pretty hard before but the past couple of months I've really just buried myself in my game. It obviously works pretty well, so I am going to keep doing it."

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