Fraser-Pryce blasted out of the blocks, heard Olympic champion Allyson Felix scream and fall to the track behind her with a torn right hamstring, and held off Murielle Ahoure of Ivory Coast and Blessing Okagbare of Nigeria to take her second gold by winning the 200 metres.
Now, the 100 and 200 champion has the 4x100 relay to go to get her first triple at a major event. Bolt already has three of those and easily qualified for Saturday's 200 final.
The big clash between Fraser-Pryce and Felix never materialized. The American was slow out of the blocks and never made up ground before she started limping at high speed and falling to the track.
"I was definitely looking for the fact that she was behind me. I was a little nervous at the same time, because I know that she is a closer of course and she is very strong," Fraser-Pryce said.
"I heard when she screamed out but I was really focused," the Jamaican added. "I decided I was running that corner and I didn't care who you were, if you were Usain Bolt behind me, I couldn't care less. I was running like my life depended on it."
As Fraser-Pryce celebrated another major win for Jamaica, Felix had her face contorted in pain. Minutes later, when the Jamaican started dancing to Bob Marley's "One Love," Felix was carried off the Luzhniki Stadium track in the arms of her brother Wes.
While Bolt and Fraser-Pryce can still win more, Mo Farah of Britain finished another championship with a long-distance double.
The 5,000-10,000 gold medallist from the London Olympics again proved there is no match for his finish after a long race, kicking for home to win the 5,000 after a first gold on the opening day of the world championships.
Over an exhilarating last lap, Farah held off Hagos Gebrhiwet of Ethiopia and Isiah Koech to make him the defining long distance runner of his age.
"There's not many athletes who have done that," Farah said. "Only the great Kenenisa Bekele, who has achieved so many things, and to be able to achieve what he has achieved is just an honour."
Bolt's qualifying run in his favourite event was more complicated than it seemed at first. After he won the 100 on Sunday, he dropped a starting block on his foot during practice and said it was still tender.
"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."
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 with a personal best time, 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.
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.
And after three silver medals on Thursday, the United States was ready to get in that golden mood again. But even if LaShawn Merritt added the 4x400 gold to the individual title by anchoring the relay team, the U.S. fell short in the men's shot put and long jump.
Favourite Ryan Whiting, the season's top performer, took silver with a toss of 21.57 metres, losing to David Storl of Germany, who retained his title with a throw of 21.73.
And despite a big tradition in the long jump, the U.S. failed to medal. Aleksandr Menkov of Russia won, beating Ignisious Gaisah of the Netherlands with a world leading effort.
Russia got off to a great start when Olympic hammer throw champion Tatyana Lysenko set a world championship record to retain her title, edging 2009 gold medallist Anita Wlodarczyk of Poland.
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.
In the gold medal standings, both the United States and Russia had five gold going into the closing weekend but the Americans had 16 overall, compared to 11 for the host nation.
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."