Golf-Rookie of the year Im celebrates with Greenbrier ace

Sept 12 (Reuters) - A day after winning the Arnold Palmer Award as the 2018-19 PGA Tour Rookie of the Year, Im Sung-jae celebrated the start of the new season in style with a hole-in-one during the opening round at the Greenbrier Classic in West Virginia on Thursday.

The feat helped the South Korean to a four-under 66 that left him four shots behind American leader Robby Shelton in White Sulphur Springs.

Im's four-iron from 223 yards at the par-three 15th landed a couple of yards in front of the hole and trickled in for his second ace of the year, making him the first since Tiger Woods to notch two on the U.S. tour before the age of 22.

Woods's ace in his first professional start in Milwaukee in 1996 is part of sporting folklore. He added another at Phoenix the following year.

Im's budding career has not generated the buzz that surrounded Woods's start, but the 21-year-old is quietly impressing his peers.

He finished 19th in the FedEx Cup standings in the season that ended last month and was the only rookie to make it to the Tour Championship.

Leader Shelton, meanwhile, described his nine-birdie effort at the Old White TPC as a "steady Eddie" performance. It was good enough to earn him a two-stroke lead over a group of five including defending champion Kevin Na.

Shelton, in his first U.S. tour start in two years and 15th overall, had to stave off nerves.

"Last night it was tough to sleep. I've been waiting for this moment all season," he said.

The 24-year-old said he had enough experience to pace himself through a tournament and planned to take the rest of the day off.

"I would grind on Monday, Tuesday, and Wednesday and wear myself out and all my good shots were gone by Thursday," he added.

"The young Robby would probably go out there (now) and start grinding and putting and hitting (balls), but I'm just going to go back and chill." (Reporting by Andrew Both in Cary, North Carolina; Editing by Ian Ransom)