And for 25-year-old Watson the victory meant more; much more, than the pounds 7,500 first prize. More even than the financial rewards - from endorsements and contracts - that will boost his income from yesterday's triumph to pounds 250,000.
The victory meant he had crossed the psychological chasm that separates the winners from the losers.
Ironically, Watson earned a psychology degree at the Kansas State University, and though top Americans including Jack Nicklaus, tipped him as being golf's superstar of the 1980's, there has been a big question mark over him. Could he win when the pressure was on? Until now, the answer had to be `no.'
Watson had a two-stroke lead going into the final round of last year's US Open - and shot a 79. He was also in contention at this year's US Masters and led this year's US Open only to blow them both. But not once did the confident Watson look like blowing his hopes in yesterday's play-off.
Not once did his swing look like letting him down. Not once did he twitch or hesitate over those vital six-foot putts. Afterwards the smiling Watson summed up his victory. He said: "I just felt it had to come. I knew I had the ability. I knew I had the shots capable of winning a major title. And in spite of those earlier disappointments I just told myself to rely on my swing. A win would come sooner or later." Watson strode to an impressive two-stroke lead after just three holes but both players were unsettled during the early part of the round.
Newton was disturbed when a crying child broke his concentration at the second hole. The Australian later claimed later that the crowds weren't well marshalled over the early holes. Watson had a row with a movie cameraman at the third hole. "I heard his camera start up on my back swing," said the American later. "I had to tell him to cut it out. But I apologised to him later."
But once the crowd and the cameraman were under control, Watson and Newton settled down to the cut and thrust battle for golf's most important prize. They both reached the turn in a level-par 36. Newton took the lead for the first and only time with a birdie at the twelfth.
But the turning point of the match came at the long 488-yards 14th hole. Newton chipped to within eight feet and looked set for a birdie. But from off the green the American took his wedge, chipped, and the ball rolled down from 30ft for an eagle three.
Newton pulled back one shot when Watson took a four at the short 16th, but the Aussie's hopes finally died when he pulled his two-iron second shot into a bunker on the edge of the 18th green. Newton, who failed to win his player's card on the US circuit last month, said: "I'm terribly disappointed, but Tom deserved to win. He putted brilliantly." But he added: "America is still my main target. I'll have another go at trying to get my card later this year or next spring."
Watson flies home today to prepare for the Canadian Open in Montreal - and is unlikely again to face the situation he met at last night's prizegiving when he was mistakenly called Tom Kite - another promising young American golfer.
Watson's stature in the sport, now he has made the breakthrough, is sure to grow... and no one will mistake him again.
FOOTNOTE: Tom Watson went on to become an Open Championship legend, winning the title five times. Jack Newton, now 50, will be commentating for Australian television at Carnoustie this week, after recovering from an accident in 1983 in which he lost an arm and an eye after accidentally walking into an aircraft propeller.
The Open returns to Carnoustie this week for the first time since 1975, when Tom Watson, a young American, won the title after an 18-hole play-off. The Daily Mirror carried this report from Ron WillsReuse content