RIO DE JANEIRO -- Canada's defence of its 112-year-old Olympic golf title is off to a strong start.

Graham DeLaet of Weyburn, Sask., fired four birdies over his first eight holes en route to a 5-under-par 66 and the clubhouse lead on Thursday until Australia's Marcus Fraser closed his round a short time later with a blistering 63. It was the first round of golf played at the Olympics since Canadian George S. Lyon won gold at the 1904 St. Louis Games.

Lyon played so long ago that he was born in Richmond, Canada West, the British colony that became Ontario after Confederation in 1867.

"It's pretty cool," DeLaet said. "First time in over 100 years and we're leading the charge here at the Olympics."

Henrik Stenson of Sweden also opened with a 66 and five players, including Germany's Alex Cejka, were right behind them at 67. David Hearn of Brantford, Ont., opened with a 2-over-par 73.

DeLaet was joined by Brazil's Adilson da Silva and South Korea's Byeong Hun An in the first group. They were greeted by a phalanx of photographers for the historic moment, with da Silva sending the opening drive down the middle of the fairway.

The historic teeing off was the first time DeLaet had felt anxious before a round of golf in years.

"The last time I can think of really being nervous was probably the (2013) Presidents Cup," he said. "There has been a couple times if you're in final groups. But not the first tee shot of the week. So it was definitely a different feeling.

"You're out there and you're playing for more than just yourself. You're playing for the flag and it's a pretty cool feeling."

Golf is in the developmental stages in the host country and the rather empty grandstands showed it. There were still groups of fans who followed the golfers around the 7,128-yard course, which has wide fairways, deep bunkers and plenty of slope.

DeLaet, with friend and retired NHL player Ray Whitney on his bag, was an impressive 31 at the turn. His lone bogey came on the 11th hole but he got that shot back on No. 13 and closed his round with another birdie.

DeLaet's approach game was in form and he was very impressed by the greens, which he said were playing "super true."

The top four players in the world -- Jason Day, Dustin Johnson, Spieth and Rory McIlroy -- are not in Rio, but the field still boasts big names like Stenson, Bubba Watson and Martin Kaymer. Play continues through Sunday.

The women's tournament begins Wednesday. Canada will be represented by Alena Sharp of Hamilton and world No. 3 Brooke Henderson of Smiths Falls, Ont.

Daniel Nestor's shot at a second Olympic tennis gold medal ended Thursday when he and partner Vasek Pospisil lost their semifinal to Spain's Rafael Nadal and Marc Lopez 7-6 (1), 7-6 (4).

The Canadian duo will face Jack Sock and Steve Johnson the United States in the bronze-medal match on Friday. Spain will play Romania's Florin Mergea and Horia Tecau in the tournament's final.

Nestor, who won Canada's only Olympic tennis medal with a gold in men's doubles in 2000, was added to this Olympic team after star Milos Raonic withdrew because of concerns over the Zika virus.

Canada's track and field team lost sprinter Kim Hyacinthe of Terrebonne, Que., native because she suffered a leg injury late last month in a 200-metre event at the London Anniversary Games.

Although cleared by doctors, Hyacinthe was unable to pass an event-specific fitness assessment in Toronto this week and was withdrawn from the Games.

Also Thursday, Canada finished fourth in women's track cycling team pursuit qualifying to advance at the event's semifinals.

Calgary's Allison Beveridge, Georgia Simmerling of West Vancouver, B.C., and the Vancouver duo of Jasmin Glaesser and Laura Brown completed the 4,000-metre event where teams race in tandem with a time of four minutes 19.599 seconds. Britain set a new world record of 4:13.260 to top the field, besting Australia's time at the 2015 world championships by 0.423 seconds.

The United States was second in 4:14.286 at the Rio Olympic Velodrome, while the Aussies clocked in at 4:19.059.

Canada now faces Britain on Saturday morning with a shot at the gold-medal final on the line, while the U.S. will line up against Australia.

In men's boxing, Toronto's Arthur Biyarslanov won his preliminary bout over Jordan's Obada Alkasbeh in the men's 64-kilogram boxing event. In men's field hockey, Canada lost 4-2 to Ireland.

Off the field of play, the CBC apologized Thursday morning after one of its Olympic commentators said on the air that a Chinese swimmer "died like a pig" during her race the night before. Swimming analyst Byron MacDonald, who didn't seem to realize his microphone was still live, made the comment following Wednesday's 4x200-metre women's relay. China placed fourth behind bronze medallist Canada with 14-year-old Ai Yanhan swimming the second leg.