Henrik Stenson and Phil Mickelson set to battle it out for Open Championship

Masters champion Danny Willett finished a frustrating week on a positive note as Henrik Stenson and Phil Mickelson prepared for what looked like being a private duel for the Open Championship.

Willett birdied two of the last three holes at Royal Troon to card a closing 71 and finish seven over par, more than 90 minutes before the final pair were due to tee off.

Looking to become the first male Swedish player to win a major, Stenson carded a third round of 68 to edge ahead of playing partner Mickelson, who at 46 would be the fourth oldest winner of any major and oldest in the Open since 1867.

And with Bill Haas five shots behind fellow American Mickelson and England's Andrew Johnston another shot back, it was hard to see the winner of the Claret Jug coming from anywhere other than the final group.

None of the first 25 players to complete their rounds had managed to break par, with Willett's 71 matched by former world number one Adam Scott and Harris English.

Jordan Spieth was on target to post the first sub-par score after an eagle on the fourth and birdies on the 10th and 11th helped the two-time major winner reach three under for the day with four holes remaining.

Spieth duly completed a three-under-par 68 which was surprisingly his first sub-par round in the majors since opening with a 66 at Augusta in April in defence of his Masters title.

Rory McIlroy had his sights set even higher when he started his round with three birdies in the first six holes, the four-time major winner also three-putting for par from just short of the green on the par-five fourth.

That lifted the 27-year-old into a tie for sixth place, albeit still nine shots off the lead as Stenson and Mickelson put the finishing touches to their preparations.