By Wednesday, Phelps had won five golds in his bid to beat Spitz's record of seven gold medals in a single
Olympics, achieved in Munich in 1972. Phelps's overall gold tally is 11.
A relieved Phelps paid tribute to Lezak after the relay, acknowledging: "Jason's last 50 meters were absolutely unbelievable."
Lezak was joined in the relay quartet by another Jewish swimmer, Texan Garrett Weber-Gale, 23, for whom the gold was a first Olympic medal. "I think Jason did a phenomenal job," he said.
"I was pounding on the block, saying the f-word. It was an amazing thing to watch. I was saying to myself: ‘If anybody in the world can pull this off, it's Jason.'"
Looking ahead to next year, Lezak said: "Maybe we can set a new world record at the Maccabiah Games."
Spitz was not in Beijing after being snubbed by the IOC. "I never got invited," said the 58-year-old stockbroker.
"They voted me one of the top five Olympians in all time so yes, I am a bit upset about it."
Also in the pool, Dara Torres, 41, claimed her 10th Olympic medal after helping the US women's 400 metres freestyle relay team to a second-placed finish.
American fencer Sada Jacobson was the first Jewish medallist of the Games, improving on her Athens bronze by taking silver in the individual sabre.
Jacobson lost an all-American final against defending champion Mariel Zagunis and was complimentary to the winner afterwards, admitting: "She earned her place today."
The medal ceremony was emotional for Jacobson, who had to borrow a handkerchief from third-placed American Rebecca Ward.
But on top of the emotion, there was what she described as "a surreal Olympic moment" as an official came to her in doping control to ask her to hurry, because "President Bush senior is waiting to see you." Jacobson's world number one ranking gave her a bye in the first round and she appeared more focused than in Athens, giving her the momentum to carry her through a series of wins.
She told the JC that she would love to compete in Israel next year at the Maccabiah Games; "I would like to go back [to visit] Israel" she said.
American marathon runner Deena Kastor, 35, will look to improve on her bronze medal at the 2004 event in Sunday's race.
On the same day, rower Josh West - the tallest member of the British squad and Britain's sole Jewish competitor in Beijing - will attempt to take gold in the final of the men's eights.
The Great Britain crew qualified for the final by winning their heat in a time of 5:25.89 over the 2,000-metre course.