Rory McIlroy blazed to a bogey-free six-under-par 66 as he sealed the lead on the first day of the 143rd Open Championship at Royal Liverpool.

The Northern Irishman has developed a bad habit of starting fast before failing to back up his good early work the second round of tournaments this year.

McIlroy began as one of the favourites and he lived up to that billing with some brilliant approach play giving him plenty of opportunities to go low on a day when perfect conditions - sun, very little wind and a receptive Hoylake links - meant players were able to take full advantage.

He almost holed his mid-iron at the second and that set the tone as he picked up two more strokes to reach the turn at three under.

Birdies followed at two of the par fives - the 10th and 16th - and the 447-yard 12th to edge one stroke ahead of Italian Matteo Manassero.

McIlroy did not pick up any shots over his closing two holes but crucially did not drop any either after coming up short of the 17th green and finding a greenside bunker.

A cluster of players posted four-under 68s, including Offaly's Shane Lowry, world number one Adam Scott, Sergio Garcia, Jim Furyk, American Brooks Koepka and Italian brothers Edoardo and Francesco Molinari, with Tiger Woods in an even bigger group a further stroke back.

Scott and Lowry were among just 13 players from the second half of the field to break par as the wind picked up in the afternoon, with defending champion Phil Mickelson two over.

2011 winner Darren Clarke and amateur Paul Dunne were best of the rest of the Irish contingent as they recorded level-par rounds of 72. Padraig Harrington shot a two-over 74, as did Graeme McDowell, with Michael Hoey one shot further back.