Henrik Stenson insists won’t back down in his final round duel with Phil Mickelson for Open glory.

The 40-year old Swede put on a ball-striking exhibition down the back nine, picking up birdie twos at the 14th and 17th to card a three under 68 to go from one behind to one ahead of the left-handed Californian magician on 12 under par.

With Bill Haas a distant six shots adrift, Stenson knows he has another golden opportunity to win his first major after finishing second to Mickelson in The Open three years ago.

But he’s also got the experience of a veteran major contender and knows what he must do to emerge the victor.

“It's a great opportunity,” he said. “But at the same time I feel like I've got nothing to lose in that sense. 

“I haven't won The Open just because I have the 54-hole lead. I'm just going to go out there and try my hardest. That's the only thing I can do.”

Always happy to play the fool and pander to the gallery for laughs, he did his bit of please the red-tops when asked if he was gunning for revenge after finishing second to Mickelson in The Open three years ago.

“There's always revenge,” Stenson said with mock serious tone, playing for laughs. “Yeah, I was one of the guys who was up there at Muirfield and Phil won it very deservingly and made a great finish; four birdies on the last six holes, I believe. 

“Yeah, it would be great to hand one back to him tomorrow, absolutely. But as we know it's going to take some good golfing to do that, but I'm certainly willing to give it a try.”

Mickelson carded a one under par 70 to remain in the hunt for his sixth major on 11 under par but he admitted that he struggled with his swing down the stretch and did well to stay in touch.

“I was off today,” said the 46-year old, who is bidding to become the oldest winner of the Claret Jug for 149 years.

“I didn't have my best stuff. My rhythm was a little quick from the top as we started downwind. 

“I was a little bit jumpy and my rhythm wasn't very good today. I found a way to kind of settle in and hit some shots and then find ways to make pars on the times that I hit some poor shots.

“Today could have been a day that got away from me, instead I shot under par and kept myself right in heading into tomorrow's final round, so I'm proud of that.”

It promises to be a 2016 version of the famous 1977 Duel in the Sun between Tom Watson and Jack Nicklaus only there has been precious little sunshine in Scotland this week.

Stenson couldn’t  resist a joke when asked by a local reporters what it would mean to him to win The Open “in the Home of Golf.”

“Yeah, it would be massive,” he said. “This is the one thing I'm looking for. It would be the icing on the cake. But at the same time I've worked hard, I've put myself in a great spot. 

“If I give myself a 50-50, it might happen, it might not happen. The sun will come up on Monday anyway, hopefully. Maybe not in Scotland, but in other parts of the world.”

Mickelson was one ahead of Stenson on 10 under starting the day with Soren Kjeldsen and Keegan Bradley three behind.

But the Dane shot 75 and the American a 76 to fall nine and 10 strokes behind Stenson on a day when Rory McIlroy failed to mount a charge, putting poorly and smashing a club in frustration as he shot 73 to fall 12 off the lead.

It was a thrilling exhibition from the leaders with Swede making birdie three of the first four holes to lead by one on 12 under before bogeys at the sixth and eighth left him one adrift heading down the back nine.

The key to his day came at the 10th, where he had to hole a 35 footer for par to remain just one behind.

“I felt like Phil had a bit more momentum at that stage, and then we both had to scramble on 11 and 12, and then I just played really solid from there on, the last six or seven holes,” Stenson said. 

Mickelson birdied the 13th to go two ahead but a two-shot swing at the 14th, where Stenson made a two after a superb five iron, set up a classic finish.

Mickelson birdied the 16th to go ahead again but another two-shot swing on the 220-yard 17th, where Mickelson bogeyed and Stenson hit a three iron in and made the putt, save the Swede take a one shot lead to the last.

There was more drama there too with Mickelson saving par from the left greenside bunker before Stenson chipped and putted for his four.

Pádraig Harrington’s money is on Mickelson in a head to head — simply because he loves the challenge of a match and has such a good short game that it can demoralise an opponent.

“I know what I would like to see tomorrow,” Stenson said. “There's no question about it. But in a way I've got a second and two thirds at The Open, so it's not like I'm looking to pick up anymore of those finishes. 

“There's only one thing that matters tomorrow. I know he's not going to back down, and I'm certainly going to try to not back down either. So it should be an exciting afternoon.

“He's one of the best to play the game in the last 15, 20 years for sure, and it's going to be a tough match. 

“But I'm looking forward to the opportunity. I've worked hard these first three days to put myself in this situation and, once again, going to try my hardest tomorrow to finish the job.”

He added: “As I said, I don't necessarily feel that much pressure tomorrow either. It's a great opportunity. But at the same time I feel like I've got nothing to lose in that sense.

“I haven't won The Open just because I have the 54-hole lead. I'm just going to go out there and try my hardest. That's the only thing I can do.”