Webb Simpson stormed to his first win of 2013 at the Shriners Hospitals for Children Open by six strokes in Las Vegas.

Simpson held a comfortable four-shot lead heading into the final round, but he showed tremendous composure at TPC Summerlin to card a five-under-par 66 and seal his first success on the PGA Tour since triumphing at the US Open last year.

"It means the world. This year, I felt like I've gotten better, just hadn't got the win. We've been working hard," he said on Sky Sports 3 after finishing well clear of Jason Bohn and Ryo Ishikawa.

The American made a great start to his round, pitching to 15 feet for birdies at the second and third holes.

He made another birdie to enter the turn on three under for his round, but then three-putted at the 12th for his only bogey of the day, which left him just three strokes clear of compatriot Bohn.

Simpson bounced back at the next hole, hitting his second shot to within a couple of feet before further birdies at the 15th and 16th provided a safeguard.

"I was playing good, solid golf, I didn't look at the leaderboard all day but the course was drying out and I knew it was playing tough," he added.

"That three-putt there set me back a bit but it was nice to birdie 13 and make a couple of more birdies, which was a good feeling."

Simpson's overall 24-under-par score ensured he becomes the fourth player in a row to triumph at this tournament with a score of at least 20 under par.

The 28-year-old has often flattered to deceive following his maiden major win at Olympic Club in 2012 and he admitted to initially struggling to cope with expectations placed on him.

"I did a little bit," he said. "I knew there was a lot of pressure on me when I moved up the world rankings and I knew a lot of people start looking at you and watching you every week.

"I felt like I learnt to deal with it towards the end of the year and I felt a lot better mentally this year."

Despite moving to within three shots of the lead with six holes left, Bohn failed to seize the initiative and his final round 66 saw him finish in a tie for second alongside Ishikawa, who never seriously threatened Simpson despite a fine six-under-par 65.

Charley Hoffman finished a further shot back after carding 64, the same score as fellow Americans Luke Guthrie and Troy Matteson, who finished in a tie for fifth along with compatriots Charles Howell III Chesson Hadley.