Jordan Spieth moved into a two-shot lead at The Open as the two-time major winner staked a strong claim for his first Claret Jug on Friday.

On a day when Royal Birkdale was buffeted by strong winds and heavy downpours, it was the young American who came out fighting to card a 69 and close on six under at the end of the second round.

He had shared the overnight lead with Matt Kuchar - who went out early and shot 71 to sit as Spieth's nearest challenger - and Brooks Koepka, who fell three strokes off the pace, level with home hope Ian Poulter.

The best round of a tough day belonged to 2015 champion Zach Johnson, who compiled a superb 66.

Spieth's intent was evident from the off as he birdied the first and, despite going on to give two shots back, a fine run from the 11th to the 15th had him seven under, with a bogey on 16 halting his progress.

Rory McIlroy's 68 saw the Northern Irishman get to one under, while world number two Hideki Matsuyama's seven at the 17th dropped him back to even par.

Reigning champion Henrik Stenson, whose accommodation was burgled during Thursday's opening round, was two over with Dustin Johnson one worse off, while several big names - including last year's runner-up Phil Mickelson - missed the cut.

The forecast rain arrived at the course around 4:30pm local time and, despite initially easing off, another downpour led to play being suspended at 5:30pm.

Kuchar was home and dry by then, having gone as low as six under, but those out later had to deal with the worst of the conditions.

Spieth had spoken of the importance of being on the right side of the draw, but his resilience was underlined by a fantastic chip-in par-saver at the 10th, followed by two birdies immediately after the brief weather delay.

He looked to be racing towards a more sizeable advantage at the summit with a nerveless eagle putt at the par-five 15th, but gave one of those strokes back at the next hole.

Still it was a fine round from the 23-year-old, with only the resurgent McIlroy, Chan Kim and Zach Johnson bettering his score.

McIlroy, who was five over through six holes in Thursday's round, sits in a tie for sixth, five back from Spieth, with Richie Ramsay one of the outsiders in the mix at two under.

Alfie Plant was the only amateur to make the cut, guaranteeing him the silver medal, but Padraig Harrington - who triumphed when the tournament was last at Birkdale in 2008 - missed out by one shot.

Hometown hero Tommy Fleetwood also just squeezed through to the weekend's play, having flirted with the cut line for much of the day.