“It's a great start [to the year], I knew I had to come out and get my name up there.
“After being five down, to make it up after 12 holes, I was really chuffed about that. I just played really well all day.”
He followed that 64 with a 74, but was back to his best with six birdies in the first 11 holes today.
Another came when he two-putted from just over the green of the long 14th, but from two in front he missed a three foot par putt on the 16th.
When Jamieson came to the hole, however, he pushed his approach into a plugged lie in the bunker and took five as well. Despite his last hole heroics, for a 15 under par total of 273, that bogey ultimately proved costly.
"Louis's a Major Champion - there's no shame in losing to him," said the World Number 100. "I gave it my all, but it wasn't to be."
He can content himself with the fact that he has started the season first, third and second, and is the early frontrunner in The Race to Dubai.
"I'll take that - absolutely," he added.
"The double bogey was a kick in the teeth, but I had tons of chances and couldn't take them."
Jamieson will move up to around 70th in the new ranking on Monday - a personal best for him too - and if he can make it into the top 50 by the end of March there will be the reward of a Masters Tournament debut.
That has been his dream ever since he was a student at Augusta State University and was allowed to play the world famous course once a year.
Thailand's Thongchai Jaidee took third place on 14 under par after closing with a round of 68, while Ireland's Padraig Harrington shot 68 to climb to fourth in the 33-man winners-only field.
He and most of the others now move on to Abu Dhabi, where world top two Rory McIlroy and Tiger Woods play for the first time in 2013 - McIlroy with new clubs.