A fired up Anthony Kim provided Phil Mickelson with a missing spark as the Ryder Cup rookie and veteran combined to help give the United States a 5 to 2 lead over Europe on Friday.

Mickelson, playing in his seventh Ryder Cup has seldom performed with the passion displayed by his team mates and a succession of U.S. captains have struggled to find ways to inspire the world number two, who has never quite seemed to embrace the competition.

While Mickelson, who has an unspectacular 9-12-4 Ryder Cup record, rebuffed calls to take on a leadership role at Valhalla, a supremely confident Kim showed the way with enthusiastic play.

The chemistry between the 23-year-old Kim and Mickelson was undeniable as the pair fought back from three down to halve the foursomes against Padraig Harrington and Robert Karlsson then repeat the feat in the afternoon to win their fourball match against Harrington and Graeme McDowell.

"I love playing with this guy," Mickelson told reporters. "Anthony has got this youthfulness to him and he has a lot of game.

"We had a lot of fun today. ...It's infectious. We played with a lot of heart and emotion.

"We were down in both matches and came back to win one and tied the other.

"We had a lot of fun playing together as partners and we are looking forward to doing it again."

Kim, who was just 10 when the three-time major winner played his first Ryder Cup in 1995, and Mickelson had lobbied Paul Azinger to put them together and the U.S. captain obliged.

Two of the more aggressive players on the PGA Tour, Kim and Mickelson gelled from the start with their successful day ending in high-fives, fist-pumps and promises of more to come.

"I was definitely a bit nervous but when you have Phil Mickelson on your side you can rely on him to hit some quality shots and it was a great day," said Kim.

"I think we are going to be pretty tough to beat.

"We are having a great time out there and when you're having a great time you're going to play good golf.

"We are looking forward to the next couple of matches."