Memphis (USA), Aug 11 : In his first event from an ankle injury, Republic of Korea's Tom Kim fired a superb 6-under 64 in the St. Jude Championship to lie one back of leader Jordan Spieth. With his pants rolled up to his calves, fans and viewers were left wondering if it was purposefully done to create airflow to his right ankle which suffered a grade 1 tear last month or just a statement of his bizarre fashion sense which caused a social media stir in the first of three FedExCup Playoffs events. 'It was wet, man, gosh. It's one of the wettest rounds I've played in a long time. It's like, I think a lot of people are actually having fun out of it, way more than I thought. I didn't want to get myself dirty. Just don't like it. I've had a really bad week once this year, so just trying to stay away from it really,' Kim explained. He was referring to his literal mud bath at the PGA Championship in May when he fell into a swamp while trying to retrieve his golf ball. With this week's venue, TPC Southwind in Memphis enduring torrential rain, Kim was being mindful of staying clean and rolled up his white pants, which choice of colour was probably his only mistake of the day. 'I didn't have unlimited pants, so I had to make sure they stayed really clean,' he said. 'A lot of people seemed to have a lot of laughs about it, but I just thought it was pretty convenient. I chose the wrong colour, obviously, but my caddie Joe (Skovron) actually said he doesn't really care what I do as long as I make birdies and eagles, so it kind of worked. Definitely not white tomorrow, that's for sure,' Kim was quoted as saying by PGA TOUR. Kim, who has one win and six other top-10s this season, showed no ill effects of his ankle woes which forced him to sit out of his defence at the Wyndham Championship last week, as he snared seven birdies against a lone bogey. Byeong Hun An, back in the Playoffs for the first time in three years, Sungjae Im and Hideki Matsuyama all opened with 67s for a share of 15th place while Si Woo Kim was a further shot back in the 70-man field. Reigning FedExCup champion Rory McIlroy opened with a 67 while Jon Rahm, who entered the Playoffs as the No. 1, uncharacteristically carded a 73. Emiliano Grillo and Collin Morikawa are joint third on 65. For the first 15 holes, Kim did not put a foot wrong as he turned in 4-under after starting the day from the 10th hole. He then made three successive birdies from the second hole and left an exclamation mark with a 31-foot birdie conversion on the fourth. He was fortunate to save a bogey on the seventh hole from seven feet following an errant drive. Spieth, the FedExCup champion in 2015, carded his lowest round of the season with five birdies and one eagle to seize his 13th career 18-hole lead/co-lead. /IANS