The British Open is likely to go down to the wire according to a couple of the tournament&aposs favourites. US Masters champion Zach Johnson and Irish fancy Padraig Harrington tipped Carnoustie&aposs frightening final three holes to sort the men from the boys. “Every Open I have played, the last two, three, four or five holes are obviously what decides the golf tournament and these three (final holes) will certainly hold up to that,” Johnson said ahead of teeing off on Thursday. “Regardless if you&aposre in the lead or just behind it&aposs going to be interesting.” “You&aposll have an opportunity to make up some ground and if you are in the lead you&aposre going to have to keep it in overdrive and try and make some pars.” “I think coming down the stretch those holes, regardless of the conditions, they&aposre going to be tough.” Harrington is on the fifth line of betting with leading sports bookmaker Centrebet. He insists being among the favourites with punters won&apost assist his quest for a maiden major title, but the Irishman can&apost envisage a long-shot claiming the Claret Jug. “This is probably one of the toughest golf courses. I think this could be a tough golf course for an outsider to win on,” Harrington said. “There&aposs a lot of golf shots that have to be hit at the end here, probably the toughest finishing hole in golf … with nine holes to play here there&aposs a lot of shots (that) have to be hit. Carnoustie is meant to be one of the toughest.” In 1999 Scotsman Paul Lawrie began the final day of the Open at Carnoustie 10 shots off the lead. With a little help from Frenchman Jean Van de Velde, Lawrie clawed his way to the title in a three-way playoff. While Van de Velde&aposs infamous and dramatic brain explosion on the final hole is well known, the course played its part across the final 18 holes. Harrington expects a number of his colleagues to have learnt their lesson eight years ago. “This time around they have the experience of &apos99. You could come out and play this golf course with no rough and it would still be a very difficult test.” “You have got a good tough golf course. The likelihood is that it&aposll be a very fair challenge all week.”