MEDINAH, Ill. —It’s another big day for the Americans, who have a commanding 8-4 lead over Europe after winning all but one foursome Saturday.

It’s the largest lead after three sessions for a U.S. team since the Ryder Cup expanded to include players from continental Europe in 1979. The Americans need 14½ points to win the Ryder Cup.

Just as they did Friday, Keegan Bradley and Phil Mickleson led the U.S. rout. Their 7-and-6 thrashing of Lee Westwood and Luke Donald tied the mark for most lopsided score in an 18-hole team match. Jason Dufner and Zach Johnson beat Nicolas Colsaerts and Sergio Garcia 2-and-1.

The Americans closed the session with Brandt Snedeker and Jim Furyk’s 1-up victory over Europe’s top team, Rory McIlroy and Graeme McDowell.

Europe got its only point from — who else? — Ian Poulter and Justin Rose, a 1-up victory over Bubba Watson and Webb Simpson.

“We’ve had so much fun,” Mickelson said. “The crowd has provided so much energy, and it’s brought our best golf out.”

Mickelson and Bradley have been fast friends since the youngster joined the PGA Tour last year, and that bond has made them the revelation of the Ryder Cup.

The 26-year-old Bradley’s enthusiasm — he sprinted out to the first tee to rile up the crowd 30 minutes before his tee time Saturday morning — has rubbed off on Mickelson, and Lefty has given Bradley the confidence to play free and easy.

And Europe hasn’t been able to do a thing about it.

Bradley and Mickelson are on such a roll they didn’t even have to putt to win their first two holes Saturday. The Europeans conceded No. 1 when Mickelson put his second within 2 feet of the pin, and they gave the Americans No. 2 after Westwood put his tee shot in the water and missed the bogey putt.

The Americans got back-to-back birdies on Nos. 9 and 10 to go 6 up. Mickelson hit a gorgeous wedge to give Bradley an 8-footer on the par-4 No. 9, and Bradley knocked it in, letting out a roar and pumping his fist.

The Americans two-putted for birdie on the par-5 10th, taking the hole when Donald saw another putt lip out.

The Americans closed out the match thanks to another big wedge shot by Mickelson. Bradley’s second shot hit a tree and landed in some rough, though Mickelson did have a clear shot at the green. He played it perfectly, the ball hitting the green about 20 feet left of the pin and trickling down a slope to within a foot of the cup.

The crowd began partying, chants of “U-S-A! U-S-A” echoing through the trees, oblivious to the fact the Europeans still had a chance to halve the hole. It didn’t matter, as Westwood botched his birdie putt and Donald missed a short one for par to end it.

It’s been a rough two days for Westwood, and captain Jose Maria Olazabal will have to decide whether to send him out again Saturday afternoon.

U.S. captain Davis Love III has a tough choice, too, with Mickelson and Bradley. It’s hard to sit a hot team, but he doesn’t want to burn them out with singles still to play Sunday.

But Mickelson made it sound as if the choice was already made.

“Historically and mathematically, the guys that have played five matches have not done as well in the singles,” Mickelson said. “We’ve got a lot of guys on this team that are playing some great golf who need to get out and play, as well. Don’t be surprised if we end up not playing because we don’t want to risk two points for one.”