Jason Lezak held on to the lead Phelps gave him, anchoring the United States to a world record in the 400-meter medley relay against an Australian team that did its best to spoil history.
But Phelps, with a big hand from three teammates, would not be denied. He eclipsed Mark Spitz's seven-gold performance at the 1972 Munich Games, an iconic performance that was surpassed by a swimmer fitting of this generation: a 23-year-old from Baltimore who loves hip-hop music, texting with his buddies and wearing his cap backward.
"I don't even know what to feel right now," Phelps said. "There's so much emotion going through my head and so much excitement. I kind of just want to see my mom."
Debbie Phelps was sitting in the stands at the Water Cube, tears streaming down her cheeks, her two daughters by her side. After getting his gold, Phelps quickly found his family, climbing through a horde of photographers to give all three a kiss.
Mom put her arm around his neck and gave him a little extra hug. Her son sure earned it.
"The Beijing Olympics has witnessed the greatest Olympian of all time - Michael Phelps of the USA," the announcer said as Phelps posed with his teammates.
Even though the Americans have never lost the medley relay at the Olympics, the latest win was hardly a breeze. When Phelps dived into the water for the butterfly - the third of four legs - the Americans were third behind Japan and Australia.
But Phelps, swimming the same distance and stroke that he used to win his seventh gold a day earlier, powered to the front on his return lap, passing off to Lezak with the Americans in front.
Australia's Eamon Sullivan tried to chase down Lezak and appeared to be gaining as they came to the wall. But Lezak touched in 3 minutes, 29.34 seconds - Phelps' seventh world record in his personal Great Haul of China.
"I was thinking not to blow the lead," Lezak said. "I was really nervous."
The Aussies took silver in 3:30.04, also under the old world record, while Japan held on for the bronze.
"Nothing is impossible," Phelps said. "With so many people saying it couldn't be done, all it takes is an imagination, and that's something I learned and something that helped me."
Phelps patted breaststroker Brendan Hansen on the head and threw his arms in the air after Lezak finished, though the Americans still had to wait a couple of tantalizing minutes for the official results to be posted. The fourth member of the team was backstroker Aaron Peirsol, who swam the leadoff leg.
Finally, it flashed on the board.