Britain broke the world record in the women's team pursuit Thursday. It could've been the United States, with St. Paul's Kelly Catlin aboard.

On the opening day of the track cycling program at the Rio Olympics, Britain, the reigning gold medalist, finished in a record 4 minutes, 13.260 seconds, breaking the mark of 4:13.683 set by Australia in February 2015.

Britain was ahead of the record pace from the moment it set off. The thing is, the U.S. team was ahead of Britain's pace until the final few laps of the 4,000-meter event before dropping away — likely to conserve energy. The U.S. finished in 4:14.286. The pace it set in qualifying bodes well for the United States in Saturday's semifinals and, possibly, final.

"We'll see what we have in the tank on Saturday," said Chloe Dygert, who joined Sarah Hammer, Jennifer Valente and Catlin in the U.S. boat.

The U.S. will face Australia in the semifinals.

Fiji takes rugby gold

Osea Kolinisau and his rugby sevens teammates can call themselves Fiji's first Olympic champions, capping their domination the past two years with a 43-7 win over Britain in the gold medal match.

Both teams were unbeaten going into the final, but only one of them has rugby sevens as a national sport. It was all but over at halftime, with the Fijians scoring five tries before the break to lead 29-0. Kolinisau scored the first of those, reaching back over his head to touch down.

The United States, including Minnesotan Garrett Bender, finished ninth, beating Spain 24-12.

Etc.

• Rafael Nadal beat 15th-seeded Gilles Simon of France 7-6 (5), 6-3 to advance to the quarterfinals in men's tennis, and then he teamed with Marc Lopez to beat Daniel Nestor and Vasek Pospisil of Canada 7-6 (1), 7-6 (4). That must've been enough for him, because he dropped out of mixed doubles just before a first-round match. Two Americans advanced: Steve Johnson will play Andy Murray in the quartrfinals of men's tournament, and Madison Keys will play Angelique Kerber in the semifinals of the women's tournament.

• Belgian Evi Van Acker, who won a bronze medal at the 2012 Olympics, became sick after racing on polluted Guanabara Bay, the first sailor to fall ill from the waters that were subject to great scrutiny leading to the Games. Her coaches said she first became ill with an intestinal infection after training on the bay in early July and was ill after sailing Wednesday. A World Sailing official said it appears to be an isolated case.

• The United States won its 18th consecutive women's water polo match, beating China 12-4. The U.S. is trying to become the first country to win consecutive Olympic titles.

• A second Kenyan track and field official was expelled from the Olympics over a doping issue. Track coach John Anzrah was sent home, accused of posing as an athlete and giving a doping sample in the athlete's name. Anzrah was caught using the athlete's accreditation card.

• Kayla Harrison became the first American to successfully defend an Olympic judo title when she forced France's Audrey Tcheumeo to tap out in the final of 78-kg competition. She won America's first judo gold medal in 2012.