The 30-year-old American played Riviera Country Club regularly while studying at the nearby University of California, Los Angeles (UCLA) and hordes of 'Bruins' fans roared him to victory at the Northern Trust Open.
"Growing up as a kid I went to a lot of these tournaments and played a lot of rounds here while at UCLA," Merrick, who was born in Long Beach, told reporters after beating compatriot Charlie Beljan at the second extra hole.
"To get a win in my hometown, it's amazing. It is a dream come true. Gosh, I can't believe it. It has not sunk in yet for sure.
"When you're alone sometimes, you think about different scenarios of winning tournaments. You dream. But to win? I can't describe it. It's so much fun."
Merrick, a journeyman professional who had twice been a runner-up on the PGA Tour, benefited from a fortunate breaks on his way to victory, the most crucial coming on the first extra hole.
While Beljan was in the middle of the fairway with a wedge in hand for his approach into the par-four 18th, Merrick faced a daunting second shot with a three-iron from a line of eucalyptus trees to the right of the fairway.
"I didn't really have a good lie down there," he said. "It was kind of matted down and I had 170 (yards) to the front and 200 to the flag. I had no shot.
"I just had to hit like a low cut around there. I was just trying to get something up there right of the flag and it came out perfectly. It just scooted through."
Merrick's second shot ended up just off the back of the green from where he chipped up to two feet and sank the par putt.
One hole later, at the driveable par-four 10th, he sealed victory with a rock-solid par after Beljan missed a five-footer to keep the playoff alive.
"It's so hard not to get ahead of yourself," Merrick said of his thoughts as he played the closing stretch in regulation with, at one point, a two-shot lead over the chasing pack.
"You get these flashes in your head thinking about winning and you're like, 'Oh, my gosh, what am I doing? I've still got four or five holes left.'
"My caddie and I kept talking, 'Slow down, slow down, play your shot as best you can and just keep moving forward.' I was nervous. I was just trying to grind it out, be tough and do the best that I could."
The grinding paid off as Merrick clinched the winner's check for $1.18 million, a two-year exemption on the PGA Tour and a spot at the Masters in April.
"I always felt like I knew I belonged out here and I knew I could play out here," said Merrick. "Going into 2010, I put way too much pressure on myself to win a tournament and I was too focused on winning tournaments rather than just playing.
"I think it just happens. You play well and you add them up at the end and sometimes you win and sometimes you don't. For my career ... I know that I'm going to get in the Masters ... It's just icing on the cake. I can't wait."
(Reporting by Mark Lamport-Stokes; Editing by Peter Rutherford)