Paul Dunne
Dunne finished the day 12 under. Getty

Irish amateur Paul Dunne, Justin Day and Louis Oosthuizen top the leader board at 12 under going into the final round of the Open Championship.

Dunne, 22, scored a six-under 66 and stands a chance of becoming the first amateur to win the Open since Bobby Jones in 1927.

Jordan Spieth lies a shot behind at 11 under after carding an excellent 66 in his pursuit of a third major having already won the Masters and US Open.

2007 and 2008 champion Padraig Harrington is also in contention after a superb 65 to finish the day 10 under.

Englishman Danny Willet topped the leaderboard after 10 holes but drove out of bounds on the 14th before finishing the day as part of a group of nine players all on nine under.

Willett failed to improve on his overnight score while Dustin Johnson also endured a frustrating day, finishing his final three holes with bogeys to drop to seven under.

Spieth meanwhile is bidding to become only the third player to win three of the four majors in one calendar year but says he is not feeling the pressure.

"I don't look at it as a negative thing, I look at it almost as an advantage," Spieth said.

"Why should it add more pressure in a negative way? If it adds more pressure, it just makes me feel like this is something that's a little more special, let's go ahead and get the job done.

"I know it's easier said than done, but when you say added pressure, most people associate that with negativity or something that can hinder what's comfortable. For me, I think it could be advantageous."