World number three Rory McIlroy has admitted that he feels 'frustrated' to have allowed his overnight lead to slip in the final round of the WGC-Cadillac Championship in Miami on Sunday.

The four-time Major winner had a three-shot advantage at the beginning of the day in Doral, but the title was won by Adam Scott, despite the Australian recording two double bogeys.

McIlroy finished tied-third and managed just one birdie, but it was not enough to challenge the top spot as he had already recorded three bogeys.

It was the second time in three weeks that McIlroy has had a troubling final round - a fortnight ago the 26-year-old was in contention for the title at the Northern Trust Open, but he dropped from tied-fifth to tied-20th on the Sunday.

"It's frustrating because it's two out of the last three weeks," Yahoo Sports quotes McIlroy as saying. "I was leading the golf tournament with 16 holes to play in Riviera.

"I was leading this golf tournament going into the back nine, and to not get the job done in either two of those instances is very frustrating.

"I feel like my game is in good shape. I just need to figure out what I'm doing in these final rounds and try to rectify it."

McIlroy's performance marks the first time that he has not seen out a Saturday-night lead since the Honda Classic in 2014.