James Hickman, who claimed the world 100m butterfly record in the morning heats, Adam Whitehead and Graeme Smith also struck gold as Britain ended the Championships with a record tally of seven first places and 21 medals overall.
However, it was Foster's performance which would have sent the fans scurrying to the telephones in a late attempt to get him named the BBC's Sports Personality of the Year.
Foster dethroned the swimming czar Alexander Popov in the heats as he reclaimed the record from the Russian after a four-year absence by 0.02sec with a time of 21.48sec. But the Bath-based 28-year-old had saved his best for the final as he obliterated the record with a stunning time of 21.31sec to see off the Dutchmen Mark Veens and Pieter van der Hoogenband.
"Watch this space," a delighted Foster, the Commonwealth champion, said afterwards. "My next target is to go under 21 seconds. I was pleased with my swim this morning, but in my heart of hearts I knew that I could go faster in the final and that nobody was going to beat me. I was just really relaxed."
Foster had come close to the record in the freestyle relay yesterday when he also broke the world 50m butterfly mark but had to accept silver as Croatia's Milos Milosevic's blistering 23.30 earned him the pounds 7,500 bonus.
Hickman, like Foster, had produced his best in the morning to add the 100m record to his 200m mark as he eclipsed the time of the Australian Michael Klim by 0.05 with 51.02sec.
The 22-year-old from Leeds was unable to repeat the feat in the final but he was always in control as he won in 51.04 to complete a Championship hat-trick following his 200m butterfly and 200m individual medley wins.
Hickman won pounds 7,500 on offer from the organisers as he overcame the challenge of the world short course champion Lars Frolander, of Sweden (51.11), with Denis Silantiev, of the Ukraine, third in 51.87.
"There is a bit more pressure in the final than in the heats because you have got to win the race," Hickman said. "But I am still very pleased to have got the world record."Reuse content