The in-form American duo won their third match of the week together after Mickelson had struck a brilliant approach to within a foot of the cup at the par-four 12th to put the US 6-3 ahead of holders Europe.
Their margin of victory matched the 7&6 wins earned by Hale Irwin and Tom Kite over Ken Brown and Des Smythat the 1979 Ryder Cup, and by Paul Azinger and Mark O'Meara over Nick Faldo and David Gilford in 1991.
"We've had so much fun," a smiling Mickelson, playing in a record ninth Ryder Cup for the US this week, told reporters. "The crowd has provided so much energy, and it's brought our best golf out."
Mickelson and Bradley's sizzling form helped spark a fast start by the US who were 5-3 ahead after the first day at Medinah Country Club and went on to grab early leads in all four matches on Saturday.
Though Europe began to mount a fightback in glorious morning sunshine, the US led in one match out on the course, trailed in the second and were all square in the third.
Jim Furyk and Brandt Snedeker were two up on Northern Irishmen Rory McIlroy and Graeme McDowell after 11 holes while Zach Johnson and Ryder Cup rookie Jason Dufner were all square with Belgian Nicolas Colsaertsand Spaniard Sergio Garcia after 11.
In the top match, Englishmen Justin Rose and Ian Poulter were two up on Bubba Watson and Webb Simpson with five holes to play in a tight, fluctuating battle.
Cup veteran Mickelson and rookie Bradley had triumphed twice together on the first day amid a flurry of fist pumps and high-fives and they continued that sizzling form with five birdies on the front nine.
Bradley, winner of last year's PGA Championship, sank a curling 12-footer to birdie the par-four ninth before furiously pumping his right fist as the crowd erupted in deafening cheers.
The US duo went six up at the 10th before sealing victory with a par at the 12th where the out-of-form Englishmen bogeyed.
Europe, under the captaincy of Jose Maria Olazabal, field one of their strongest ever line-ups but face a challenging task to retain the trophy with the US having lost only three times on home soil since the matches began in 1927.
"We do have to change the momentum," Spaniard Olazabal said after his
team were outplayed by the Americans on the opening day. "We need to
have a great day tomorrow, both morning and afternoon sessions."