Branden Grace and Luke Donald carded five-under-par 66s to take a one-shot lead at the RBC Heritage in Hilton Head Island, South Carolina.
The leaders are closely followed by world number one Jason Day, who is currently on four-under and in a tie for third with Matt Kuchar, David Lingmerth and Tony Finau.
Grace, who failed to make the cut at the Masters last week, was in superb form on the front nine as he began with consecutive birdies at the first and second before proceeding to make two more at the fifth and ninth.
The South African continued to impress on the back nine as converted a 25-foot birdie putt at the 13th before another birdie followed two holes later. Just when it seemed that the 27-year-old was set to have a bogey-free round, he missed an eight-foot par putt to record his lone bogey of the round at the 16th.
Donald, who has not played since finishing in a tie for 26th at the Puerto Rico Open in March, kicked off his round with three birdies on the first six holes before faltering at the eighth, where he registered his only bogey of the round after missing a 16-foot par putt.
The Englishman, who is searching for his first title since 2012 and came close to retiring last year, enjoyed a productive back nine as he made three more birdies, which included a holed 16-foot putt at the 11th.
Day fired an excellent round of 67, which began with a pair of birdies on the front nine. The Australian maintained his form for a majority of the back nine as he holed a 27-foot birdie putt at the 11th before going on to make two more birdies at the 12th and 15th.
The world number one was on track to join Grace and Donald atop the leaderboard, but he was forced to settle for a share of third after he took an unplayable lie at the front center green side bunker at the 18th, which led to him making his lone bogey of the round.
Kuchar made four birdies during his round, which included a superb 36-foot putt at the 12th, while Lingmerth was in sensational form with the putter as he recorded five birdies on the front nine before committing his lone blemish at the 14th. Finau made three birdies, a bogey and an eagle at the par-four ninth, where his tee shot fell just three-feet short of the cup.
Meanwhile, 2015 Open winner Zac Johnson, who missed the cut at the Masters, endured a turbulent round as he made three birdies and three bogeys during his round of level-par 71.
The US President was among the viewers watching the TaylorMade Driving Relief.
The US President phoned in as McIlroy played in a Sunday fundraiser for coronavirus victims.
Syme donated his prize money to charity.
‘This is the life of a caddie…’
The Northern Irishman is ranked number one in the world.
Players entering the United States will face a 14-day quarantine period, while a strict testing regime will be in place at each tournament.
The experienced duo will be involved at Whistling Straits.
The world number 98 intends to split the 10,000 euros prize money between his own charity and a hospital in his native Rotterdam.
The biennial event between Europe and the United States is scheduled to take place from September 25-27.