"It means a lot to win my third victory on Tour and playing against who I played today," said Larrazabal.
"Of course, I play against myself but I knew who I also had behind me in Mickelson. I have just beaten two of the three most talented guys in my era, and in the last era, as well in Phil Mickelson and Rory.
Mickelson was left counting the cost of incurring a shot penalty after a double hit while playing from brush on the 13th hole of the National course.
The British Open champion, who was leading at the time, finished the hole with a triple-bogey seven.
"I was sitting at the presentation ceremony I said to myself: 'Pablo? What are you doing here?' I've got Rory McIlroy on my left and I am shaking the hand of Phil Mickelson on my right. It's very special for me," added Larrazabal after collecting the trophy.
"But it's been a long journey and a lot of work since my last win in Munich, and only my team and my family know how hard I have worked for this victory with no holidays, and not too many days off this winter, just working hard to arrive here properly and in form to Abu Dhabi. So, yes happy days."
While Mickelson was returning home for his first PGA event of the New Year, at this coming week's Farmers Insurance Open at Torrey Pines, McIlroy is returning to nearby Dubai to continue working on his game.
It is the second occasion in three years he has let slip victory in Abu Dhabi because of a rules violation.
"It happens, it happens but it never crossed my mind I might double hit it," Mickelson said.
"I was just trying to dribble it out of the bush because I couldn't get the unplayable penalty lie to give me a shot without stroke and distance and I felt it was worth the risk. It not only cost a penalty shot, but it also stopped the ball from going to a spot where I could hit again.
"So after that I got refocused and got aggressive and made some birdies and gave myself a chance. If Pablo had not birdied the last hole to win, I would have gotten into a play-off, and so I give him a lot of credit for finishing the tournament off the right way," he added.
McIlroy had been penalized for illegally brushing sand off his line on the final day of the 2012 event before losing by a stroke to England's Robert Rock.
On Saturday, the double Major winner was slapped with a two-shot penalty after being reported by the caddy of another player in not taking 'full relief' from a spectator cross walk.
"I can't describe how frustrating it is and feeling like I should be standing here at 15-under par for the tournament and winning by one," McIlroy said.
"It is a very positive start to the season so I'm not to let one little negative ruin that. It was not to I finished one behind on the 18th that it started he o dawn on me if what happened yesterday had not happened, I would have won.
"But Pablo played well, and I can't take anything away from him. When he needed to, he hit the shots, and the two shots he hit into 18 were straight out of the drawer, so fair play to him.
"It's good to see. He's a good guy, one of my closer friends out here and good to see him get the win."
Larrazabal moved into seventh place in the Race to Dubai and to 12th on the European Ryder Cup Team points table.
As well, the current World No. 103 ranked player should move inside the top-64 on the rankings when they are adjusted Monday and that will guarantee the Spaniard a first-ever place in next month's Accenture Match-Play Championship in Arizona.