Defending champion Hatton, who began the day with a five-shot lead, held off the late challenge of Ross Fisher, whose brilliant 61 set a new course record, and Frenchman Victor Dubuisson to become the first man to retain the crown.
Hatton, 25, opened up a seven-shot lead with four birdies on the front nine and gained a further shot on the 14th — he dropped only two shots during the tournament — to finish three ahead of fellow Englishman Fisher for his second European Tour title.
Fisher, who played himself into contention by gaining six shots in his last seven holes on Saturday, maintained his sizzling form by threatening to close with a record-breaking 59.
Fisher carded seven birdies on the front nine and hit four more successive birdies from the 12th to stand at 11 under, but fell short of the magical figure as he parred the final three holes.
Dubuisson had also set himself up for a chance of a new course record with three holes to play, having carded 10 birdies to stand 10 under after the 15th, but he three-putted the 16th to drop his first shot of the day and parred the last two holes for a nine-under 63.
Scotland’s Marc Warren and England’s Robert Rock both carded final-round 66s to tie for fourth place, with Frenchman Gregory Bourdy, who shot a 71 after starting the day as Hatton’s closest challenger.
Hatton said afterwards: “Obviously I’m very happy. This week was the first time I had ever defended a title or had the chance to try and do it. You know, it felt like it was a lot harder this year, well, winning this year, than it was last year. I’m so happy that I managed to get over the line.
“I didn’t see a leaderboard on the back nine until the 16th green, when I saw he (Ross Fisher) was at 21 and I was thinking how well he was going today. So you know, fair play to Fish. It was an incredible round of golf, and he certainly did push me all the way.
“I’m not a very technical person with the golf swing or things like that. I like to keep things really simple. That’s what I went back to after the US PGA, and, you know, obviously I’ve got a new caddie on the bag at the moment, my good friend, Jonathan. He’s done a great job since we started working together in Switzerland. I think having a friend on the bag is keeping me relaxed. I feel so much more comfortable with my game.
“I played with Jamie (Dornan) last year, and we had a good time and it was good fun. I was happy that we could play again this year. Obviously it’s a winning formula which helps me, so perhaps he should play with me every week. But no, obviously it was great fun to have him here, and we get on really well. Hopefully we can do it again next year.”
Ross Fisher said: “I knew we were starting off kind of playing for second. Obviously Tyrrell had a big lead but after my performance yesterday, I felt like there was a good one in me today around here, because you saw the forecast, and it was still a bit chilly but there wasn’t much breeze.
“When you get St Andrews on a day like this, it’s definitely doable, but you still have to hit the shots. I got off to a fast start and managed to make some good putts early on. It was a shame not to birdie the last for a 60, but I’m not going to complain too much with a 61.”