Brian Viner: He's slim and trim, but 'Mild Thing' Daly can still cut loose

On the par-four 16th, most players hit irons, Woods hit a three-wood, but Daly got out the driver without hesitation, and boomed the ball to within 25 yards of the green

A year after Tom Watson turned the clock back to Turnberry 1977 on the opening day of the Open, John Daly kindled memories of the 1995 championship at St Andrews, posting a six-under-par 66 that, in fact, bettered his first-round score 15 years ago. Daly went on to win that year following a play-off with Costantino Rocca, and while nobody is counting chickens with three rounds to play, he has at least given himself a chance of settling his $1m debt to the US taxman with a single pay cheque.

The other reason not to bother counting chickens is that they no longer go missing in Daly's vicinity, turning up fried and on his plate. Since the man formerly known as "Wild Thing" had a gastric band fitted in February last year he has shed more than four stone, and no longer consumes alcohol and junk food by the golf-cart load, indeed hardly at all.

He is happy these days to go by the nickname "Mild Thing", and cut an almost svelte figure on the Old Course yesterday, at least by comparison with the Sumo wrestler that he once resembled. Afterwards he admitted that at his heaviest he had invariably run out of stamina after 12 holes, simply becoming too tired and hungry to focus on the job in hand.

Yesterday, Daly saw the job through, making the most of a 7.25am starting time and the day's most benign conditions by playing wonderful golf in a round that was almost as notable for what it wasn't, as for what it was. Had he holed even half of the putts he missed from within 10ft, he would have become the first man to record a 62 or better in major championship golf. His only bogey of the round came on the 17th, the notorious Road Hole, where he chose a seven-iron for his 171-yard second shot but "flushed" it over the green and on to the path beyond.

As ever with an in-form Daly, the secret of his success was his prodigious length off the tee, taking dozens of the Old Course's 112 bunkers out of play in a way that even the other similarly big hitters out there were not bold enough, or stupid enough, to attempt.

On the par-four 16th, for example, out-of-bounds all the way along the right, and some fiendish bunkers on the left, including the cluster of three charmingly known as the Principal's Nose, dictate caution for every other golfer in the field. The majority of them hit irons there. A couple of hours later, more aggressively than most, Tiger Woods hit a three-wood. But Daly pulled out the driver without hesitation, and boomed the ball to within only 25 yards or so of the green, enabling him to attack the pin with his second shot.

His playing partners Andrew Coltart and Noh Seung-yul, hitting their seconds from at least 100 yards back down the fairway, could have been forgiven for wondering whether they were playing the same game. Daly might have shed the epithet "Wild Thing" along with all that blubber, but his original golfing philosophy, "grip it '*rip it", hasn't changed.

Nor has his idiosyncratic dress sense. Yesterday he sported a pair of swirly-patterned trousers that really belonged to a bad LSD trip, and following him round in a matching miniskirt was his girlfriend, former Hooters waitress Anna Cladakis. Daly's friends credit Cladakis for helping to keep him on the straight and narrow, but her conservatism clearly does not extend to his wardrobe. By the 18th green, The Independent quietly asked her whether she and Daly have matching outfits planned for the next three days, and she nodded enthusiastically, adding: "You should see what he's got... oh my God."

What Daly also has is a candour and generosity of spirit that makes him a hugely popular turn at post-round press conferences. It is not so long since a string of self-destructive binges compelled a fellow US Tour player to say of him that he had stopped being a golfer and was now a "freak show", yet the only freakish things about him on his latest return to St Andrews – his favourite course "on earth" – were the length of his drives and the colour of his trousers.

"I'm 44, I've learnt a lot," he said afterwards, reflecting on his more sober lifestyle. "I've never run from my mistakes. I've screwed up an awful lot, not just on tour but in other aspects of life. And like I said before, I think it's how you come back and deal with it."

Alongside him, another comeback had unfolded, less colourful but no less satisfying. Coltart matched Daly's 66, two terrific nines of 33 from a man who in recent years has been better known as an on-course analyst for Radio 5 Live, and for being Lee Westwood's brother-in-law.

A former Ryder Cup player, Coltart lost his card and at one stage considered giving up the game altogether, but persevered and at Sunningdale managed to pre-qualify for this Open. A place high on the first-day leader board was his reward, although he admitted to nerves as he prepared to drive on the Road Hole, with all its card-wrecking potential. "There should," he observed wryly, "be a toilet fairly close to that tee."