Rory McIlroy continued to lead the way both on and off the course, shooting a bogey-free eight-under 62 at the Travelers Championship on Thursday.

After defending his title at the Canadian Open for a 21st PGA Tour win a fortnight ago, following up with a top-five finish at the U.S. Open, McIlroy opened with five birdies over the front nine on the TPC at River Highlands course.

The most vocal of critics against the LIV Golf Invitational Series, the in-form Northern Irishman then closed with two birdies over the final four holes, including a birdie on the par-four 18th to punctuate a blistering opening round.

The birdies were flying at the opening day in Cromwell however, with JT Poston taking a share of the opening-round lead with an eight-under of his own.

They hold a one-stroke lead over Xander Schauffele, who closed with four birdies over the final six holes on Thursday to finish on a seven-under 63, tied for second with Scotsman Martin Laird.

Schauffele was in fine touch with his approach game, hitting the ball particularly cleanly and could have finished with an even lower score had he capitalised with his putter.

They were followed by a three-way tie for third, with Patrick Cantlay, Webb Simpson and Charles Howell III all posting scores of six-under in the opening round.

Meanwhile, Cam Davis and Matthew NeSmith share fourth place after the opening 18 holes, finishing on five-under for the round.

While others shone in Cromwell, Jordan Spieth had a tough day out for his opening round despite three birdies over the last five holes, finishing with a five-over 75 for the day.

He will have plenty of work to do on Friday just to make the cut, while world number one Scottie Scheffler posted a two-under 68.