Phil Mickelson
Mickelson sank the final shot on the 18th to give the US a slender lead.Getty

The United States have drawn first blood in the 2014 Ryder Cup after taking a 2 1/2-1 1/2 lead in the opening fourballs session at Gleneagles.

Phil Mickelson and partner Keegan Bradley edged out Rory McIlory and Sergio Garcia on the par five 18th to secure the most slender of leads ahead of the afternoon's foursome session.

The final match-up of the morning was left to decide the opening session as an impressive rally from Rickie Fowler and Jimmy Walker levelled the contest at a point and a half each, following wins for Justin Rose and Henrik Stenson and Jordan Spieth and Patrick Reed.

Europe took the first point of the morning as Rose and Stenson eased to a 5&4 win over Bubba Watson and Webb Simpson in the opening match.

The European duo took the lead from the second hole and never looked back as Masters champion Watson and Simpson failed to sink a single birdie.

Tom Watson's side would draw level however as debutants Spieth and Reed secured an emphatic 5&4 over European newcomer Stephen Gallacher and Ian Poulter, who endured his worst ever Ryder Cup performance.

Watson's decision to pair the two rookies proved to be a masterstroke as the American duo, 21 and 24 respectively, opened up the biggest deficit of the afternoon as they went six up on the 11th hole.

Despite holding a three up advantage after four, Paul McGinley's second pair of Martin Kaymer and Thomas Bjorn surrendered their commanding lead as Fowler and Walker drew level in exhilarating fashion.

German Kaymer had the opportunity to seal the point for Europe on the 18th but putted wide, allowing Walker, who sank a wonderful eagle on the eighth from the inside bunker to spark the comeback, to take a half point.

It was left to the final pairs to decide the contest as Europe went into the final hole one up. Both McIlroy and Garcia found themselves stranded in the bunker guarding the green of their fourth shot however, allowing Mickelson to secure the spoils with a two-footer.

Friday foursomes pairings:

Jamie Donaldson and Lee Westwood (Europe) against Jim Furyk and Matt Kuchar (USA)

Justin Rose and Henrik Stenson (Europe) against Hunter Mahan and Zach Johnson (USA)

Rory McIlroy and Sergio Garcia (Europe) v Jimmy Walker and Ricky Fowler (USA)

Victor Dubuisson and Graeme McDowell (Europe) v Phil Mickelson and Keegan Bradley (USA)