Scottie Scheffler stormed into a share of the first-round lead at the US PGA Championship, while Rory McIlroy endured a tough opening day, trailing by seven shots. The world number one, playing in one of the final groups at Aronimink Golf Club in southwest Philadelphia, navigated a course where low scores were hard to come by, finishing at three-under par.

Scheffler's round placed him in a seven-way tie at the top of a jam-packed leaderboard, which includes German star Martin Kaymer—12 years removed from his last major victory. The depth of the field is remarkable, with a record 33 players within two shots of the lead, surpassing the previous mark of 28 set at the 1993 Open Championship. Among them are 12 major champions, setting the stage for a thrilling weekend.

Scheffler started quietly but stumbled with a bogey on the fifth hole. He quickly rebounded with consecutive birdies at six and seven, then showcased his grit by saving par from a greenside bunker on the daunting 245-yard par-three eighth. A 28-foot birdie putt on the 10th moved him to two-under, and he joined the leaders with another birdie at 11. Despite a frustrated demeanor on the front nine, Scheffler's rise up the leaderboard felt inevitable. A birdie on 16 offset a bogey on 14, securing his first share of a major lead after the opening round.

The defending champion played alongside world numbers four and seven, Matt Fitzpatrick and Justin Rose. Rose battled early bogeys at three and six but found his rhythm with birdies at 13 and 14, the latter a chip-in from a bunker that thrilled the crowd. Fitzpatrick grinded through 13 straight pars before a bogey and a birdie left him at even par.

Major winners Xander Schauffele, Patrick Reed, and Shane Lowry—who chipped in for an eagle on nine—are just one shot off the pace. The course, with its massive, undulating greens, proved a tough test, making par saves a priority and keeping the field tightly bunched.

For McIlroy, who anticipated a challenging round, the day was a struggle as Aronimink bared its teeth, reminding everyone why it's a championship venue. As the tournament unfolds, all eyes will be on Scheffler and the chasing pack, with the leaderboard too close to call.