The results proved discomfiting, which makes it almost certain Felix will not try another 200-400 double at the 2012
"if I had to say right now, it would not be high on my list of things to do," Felix said after taking third in Friday's 200 final.
Clearly out of energy after winning the silver medal in the 400 four days ago, Felix had nothing left in the final 50 meters of Friday's 200 final as she finished behind
Each won her second individual gold medal of the meet in Daegu, South Korea. Campbell-Brown had taken silver behind Jeter in the 100.
Campbell-Brown, the two-time Olympic 200 champion, got a great start and won with a solid time of 22.22 seconds into a 2.2 mile-per-hour headwind. Jeter, who tied up at the end after challenging Campbell-Brown for the lead, clocked 22.37 for 22.42 for Felix and 22.61 for fourth finisher Shalonda Solomon of the U.S.
This was the first time Felix had run two individual events in a global championship.
"I do not have any regrets," Felix said. "I tried to do something new, and it gives me a lot of motivation for next year.
"The 200 will be very important next year. I think the 400 took a lot out of me."
Felix has twice finished second to Campbell-Brown in the Olympic 200.
Despite a surprising total flop in the shotput, Team USA added two golds to its meet-leading total, now nine.
Long jumper Dwight Phillips, one of the best big meet performers in history, shook off an injury-marred season to take a fourth world title. He had finished just 10th at the U.S. Championships in June and competed just three times this season before worlds.
Phillips, the 2004 Olympic champion, won with a jump of 27 feet, 8 3/4 inches. Michael Watt of Australia was second at 27-4.
And LaShawn Merritt's strategically and athletically brilliant anchor leg rallied the US to victory in the 4 x 400 relay.
The U.S. quartet had two men who ran the 400 hurdles (Bershawn Jackson and Angelo Taylor) following Greg Nixon. They clocked 2:59.31, with South Africa second (2:59.87) and Jamaica third (3:00.10).
After ending long gold-medal droughts in three events Thursday, the U.S. went the other way in the shotput, failing to win a medal for the first time since 1991 and failing to win a medal for the first time since 1991.
The US results: 2009 champion Christian Cantwell was fourth (70-1); 2007 champion Reese Hoffa fifth (68-10 1/2); Ryan Whiting seventh (68-1); 2005 champion Adam Nelson 8th (66-7).
"After the qualifying, a lot of my competitors were asking, `Who is David Storl?' Now they know," Storl said.
Showing no ill effects of having been disqualified in the 100-meter final, Usain Bolt of Jamaica cruised into Saturday's 200-meter final, playing to the crowd as usual and winning two races easily, jogging at the finish.
Both times, he waited to make sure there would not be another false start. His reaction times, .314 seconds in the first round and .207 in the semis, were well above the allowable .1. His times, both into headwinds, were 20.30 and 20.31.
U.S. champion Walter Dix also won both his 200 races.
Bolt looks unbeatable and obviously feels that way, saying after the semifinal he expected no challenges if he gets a good start in the final.