For the past couple of years, Im Sung-jae has been hands down the best South Korean player on the PGA Tour, a consistent workhorse hanging around the top 20 in the world rankings with no countryman nearby.

Today, Im has company: the 20-year-old sensation Kim Joo-hyung. Last week, Kim, on the heels of his first PGA Tour win at the Wyndham Championship, reached a career-high No. 19 in the world rankings to supplant Im, who stayed at No. 20, as the top South Korean.

The two golfers traded places this week, with Im moving up to No. 19 and Kim dropping a notch to 20th.

Im and Kim could be doing just that for weeks, months or even years to come, an exciting prospect for the golf-crazed country thirsty for big PGA Tour stars who could match the dominance of their countrywomen in LPGA.

Im, 24, says the nature of rivalry between himself and Kim, if one even exists, is friendly.

"It was pretty amazing to see two Korean players inside the top 20 in the world," Im said in an online press conference with the South Korean media Wednesday morning from Atlanta, where he's gearing up for the season-ending Tour Championship.

"I had never seen anything like that, and it is driving me to work even harder," Im added. "I think we really push each other. But we're such good friends. We joke around and pull pranks on each other. We don't really have an intense rivalry between us."

About to wrap up his fourth PGA Tour season, Im, who has two career victories, understands just how difficult the grind can be. He said he was "quite surprised" by how well Kim has played this summer, despite having so much uncertainty hanging over his head week in and week out as a nonmember.

"He is a hard working player, and it is easy to see he wants to keep getting better," Im said. "I think he can be a very successful player on the tour for a long time if he can keep that up."

In perhaps the clearest indication of his consistency, Im will play in his fourth consecutive Tour Championship, a tournament open only to the top 30 players in FedEx Cup points after the regular season and two playoff tournaments.

Im, who is 10th in the FedEx Cup standings this year, is the first South Korean to have accomplished that long of a streak since the current playoff format was put in place in 2007. Im's streak began in the 2018-2019 season, when he was named the PGA Tour Rookie of the Year.

In this week's field, only six others will be playing in their fourth Tour Championship in a row, and the list includes major champions and an Olympic gold medalist: Rory McIlroy, Justin Thomas, Tony Finau, Jon Rahm, Xander Schauffele and Hideki Matsuyama.

"It's a meaningful achievement to be the first Korean to play here four years in a row," Im said. "This means I've been playing consistent golf over the years. I am proud of myself."

In September, Im and Kim will put aside their budding rivalry and compete as teammates at the Presidents Cup, a biennial match play competition pitting non-European international golfers against Americans. They were among the top eight players to earn automatic selections for the International Team, with Im finishing third and Kim coming in at fifth in performance-based points.

Im will be playing at his second Presidents Cup and Kim will be a rookie. With chemistry between players at a premium in team competitions such as this, Im and Kim will likely be paired for foursome and four-ball matches.

"If we do end up playing together, it's going to be so much fun," Im said, adding that the two have even discussed how they should celebrate key shots and putts during the Presidents Cup.

"We may do something crazy, just to rattle the opponents and get inside their heads," Im quipped.

And having fun is also Im's primary objective this week. Under the "starting strokes" system, the No. 1 player in the FedEx Cup standings, Scottie Scheffler, will begin the Tour Championship at 10-under. Im and the rest of the players ranked between sixth and 10th will start at four-under.

Making up that much ground over four days will be such a tall order that Im said he will not worry about trying to rally for a win.

"I am speaking from experience, and winning on the PGA Tour is incredibly hard," Im said. "I almost think you need help from above to win. You have to be perfect for four days, and if you stumble just for one day, it's going to be difficult to win because there are so many great players out here.

"If I can enjoy myself out there for four days, then results will follow," Im added. "But if I get too caught up in trying to chase down the leader, I won't play so well." (Yonhap)