Earlier this week, high jumper Derek Drouin won a bronze, and Brianne Theisen-Eaton took silver in the heptathlon. Damian Warner captured bronze in the decathlon last week.
In 1995, Donovan Bailey and Bruny Surin finished 1-2 in the men's 100 metres and helped the 4x100 relay team to gold, and Mike Smith took bronze in the decathlon.
Armstrong, the 2011 world silver medallist from Kamloops, B.C., tossed a season-best 21.34 metres on his fifth attempt in Friday's final at Luzhniki Stadium. His second try (21.10m) was also his best of the season at the time.
"I just feel amazing," Armstrong said. "My coach and I worked really hard, I made some really good choices this year."
David Storl of Germany retained his title after his throw of 21.73 metres was first flagged for a foul but later reinstated.
Ryan Whiting of the United States, the season's top performer, took silver with a toss of 21.57.
Bolt eases into 200m final
Usain Bolt didn't have to pressure his taped-up tender right foot, coasting into the 200-metre final and setting himself up for a second gold medal.
With only two assured qualification spots from his heat, the 100 champion switched into a higher gear at the end of his race when, unexpectedly, Anaso Jobodwana appeared on his left shoulder.
Bolt momentarily gritted his teeth but soon turned them into a grin as he held off the South African and took first place in his semifinal heat in 20.12 seconds. He never showed any unease about his right foot.
"At the last minute when I started slowing down, I heard South Africa on my inside," Bolt said. "I didn't want to lose the race so I picked up the speed again."
Curtis Mitchell was the top qualifier in 19.97, but saw all his American teammates eliminated from the final. Isiah Young missed it by .03 seconds.
Bolt was joined in the final by Jamaican teammates Nickel Ashmeade and Warren Weir.
Canada's Tremaine Harris ran a solid 20.68, but failed to move on in his heat.
Bolt had been troubled by a sore foot since he regained his 100 title on Sunday. He said he dropped a starting block on his foot in training.
"I just dropped it on my foot. It wasn't on purpose. It was just a mistake," Bolt said. "I was in training, and I was moving it and dropped it on my foot."
If Bolt wins, he goes into the 4x100 relay seeking to win three golds at the worlds for the second time, matching his feat at the last two Olympics.
Fraser-Pryce doubles down
Shelly-Ann Fraser-Pryce completed a sprint double, adding the 200-metre gold to her 100 title.
The Jamaican won the race in 22.17 seconds.
Murielle Ahoure of Ivory Coast took silver in 22.32 and Blessing Okagbare of Nigeria, who finished second in the long jump and sixth in the 100, took bronze in 22.32.
Three-time world champion Allyson Felix of the United States dropped to the track early in the race grabbing her right leg and did not finish.
Farah grabs 2nd gold
Mo Farah of Britain completed back-to-back doubles in long distance races by winning the 5,000-metre gold medal.
Farah had already won the 10,000 at the start of the championships and now has repeated the double he achieved at last year's London Olympics. He also won his second consecutive 5,000 title.
The Briton broke away from the pack with about 600 metres to go and fended off challenges from Isaiah Koech of Kenya and Hagos Gebrhiwet of Ethiopia in the home straight to win in 13 minutes, 26.98 seconds.
Gebrhiwet took the silver in 13:27.26, the same time credited to Koech for the bronze.
Canadian Brennan runs season-best
In the men's 1,500 metres, Canada's Nathan Brannan posted a season-best time of 3:36.59 in the semifinals and qualified for the final in seventh spot.
The Canadian women's 4x400 relay team set a season best of 3:31.09, but it wasn't enough to qualify for the final.
In the women's 100 hurdles, Canadian hopefuls Angela Whyte and Jessica Zelinka fared well in qualifying for the semifinals of the women's 100-metre hurdles, clocking in seventh (12.93) and 17th (13.15), respectively, behind front-runner Briana Rollins (12.55) of the U.S.
Olympic and defending champion Sally Pearson shook of the injury worries that slowed her this season and set a season's best time of 12.62 seconds in her heat, still .07 seconds behind Rollins.
Dawn Harper, the 2008 Olympic champion from the United States, finished only third in her heat, but still advanced.
In women's javelin, Canada's Krista Woodward failed to meet the qualifying standard of 61.50 metres or place at least 12th, settling for a toss of 58.86 and 17th overall.
Americans retain 4x400 crown
The United States defended its title in the men's 4x400-metre relay.
David Verburg, Tony McQuay, Arman Hall and LaShawn Merritt won the race in 2 minutes, 58.71 seconds.
Jamaica was second in 2:59.88 and Russia was third in 2:59.90.
Russian wins long jump gold
Aleksandr Menkov of Russia won the men's long jump, beating Ignisious Gaisah of the Netherlands with a world leading effort.
Luis Rivera of Mexico took bronze.
Menkov jumped 8.56 metres on his fifth attempt to take gold, while the Ghana-born Gaisah set a national record for his adopted nation with a mark of 8.29. Rivera took bronze with 8.27.
Olympic champion Greg Rutherford of Britain was eliminated in qualifying and defending champion Dwight Phillips of the United States, a four-time winner of the event, finished 11th.
Lysenko takes hammer throw
Olympic hammer throw champion Tatyana Lysenko of Russia set a world championship record to retain her title, edging 2009 gold medallist Anita Wlodarczyk of Poland.
Zhang Wenxiu of China took bronze.
In a seesaw competition, Lysenko finally got the upper hand with a throw of 78.80 metres on her fourth attempt, edging Wlodarczyk by a mere 34 centimetres. Zhang had a mark of 75.58.
World-record holder Betty Heidler of Gemany failed to reach the final.
Isinbayeva backs off
Off the track, pole vault great Yelena Isinbayeva backed off from her comments criticizing homosexuality.
The Russian said she "may have been misunderstood" when she condemned homosexuality and criticized Swedish high jumper Emma Green Tregaro for painting her fingernails in the rainbow colours to express support for gays and lesbians.
"English is not my first language," Isinbayeva said. "Let me state in the strongest terms that I am opposed to any discrimination against gay people."