Wyndham Clark leads the Canadian Open after the first round of play, shooting a seven-under 63 in Toronto on Thursday.

Amid an awkward atmosphere around the course with LIV Golf's commencement outside London on Thursday and suspension for players part of the rebel tour, Clark was able to hold his lead against the afternoon wave of players.

After securing a berth at next weekend's U.S. Open in a qualifier on Monday, the 28-year-old carried some confidence into the opening day at St. George's Golf and Country Club, starting with five birdies on the opening nine.

He went bogey-free on the closing nine holes, scoring birdies on the par-four fourth and seventh holes.

Matt Fitzpatrick finished the day a stroke back in second place, after nailing four consecutive birdies between the eighth and 11th to eventually end with a six-under 64.

Harold Varner III and Doug Ghim sit a further stroke back on five-under, while defending champion Rory McIlroy heads a four-way tie on four-under.

McIlroy has had to wait three years to defend his title, with Covid-19 halting the tournament over the previous two years. He set the tournament record over 72 holes to defeat Shane Lowry in 2020 at Hamilton, and posted six birdies in his opening round on Thursday.

US PGA Championship winner Justin Thomas, who wanted to repeat his method of playing the week before a major, opened with a one-under 69.

The Masters champion Scottie Scheffler also posted a score of one-under, closing with consecutive bogeys on 17 and 18.

In a strong field with five of the world's top 10 players competing, Sam Burns opened with a three-under 67, but Cameron Smith posted a six-over 76 after four bogeys in his closing six holes.