|-10 D Johnson (US) (after 13), -9 Willett (Eng), -8 Lawrie (Sco) (12), Day (Aus) (11), -7 Warren (Sco), Z Johnson (US), Scott (Aus), Streb (US), Oosthuizen (SA) (11)|
|Selected others:-6 Dunne (Ire) (18) *am, Donald (Eng) (18); -5 Rose (Eng) (18), Spieth (US) (13), -1 Fowler (US) (18); +5 Woods (US) (11); +10 Faldo (Eng) (18); +12 T Watson (US) (18). Full leaderboard|
American Dustin Johnson leads The Open after a rain-disrupted second day at St Andrews, one shot clear of England's clubhouse leader Danny Willett.
Play was delayed for more than three hours because of heavy rain, meaning Johnson and 41 others will resume their second rounds at 07:00 BST on Saturday.
World number four Johnson is 10 under after 13 holes, while Willett carded a three-under 69 for nine under overall.
Grand Slam-chasing Jordan Spieth is tied for 15th on five under after 13.
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Scotland's former champion Paul Lawrie (after 12) and Australia's Jason Day (after 11) are joint third on eight under.
Scotland's Marc Warren(69), former Masters champions Zach Johnson (71) and Adam Scott (67) are in the clubhouse on seven under, while South Africa's Louis Oosthuizen, winner at St Andrews in 2010, is on the same score after 11.
Three-time champion Tiger Woods is five over after 11 and is set to miss only his second cut in 19 Open appearances.
Play ended at 21:55 BST in near darkness to allow five-time champion Tom Watson, in his final appearance at St Andrews, to complete his round in front of the clubhouse rather than have to come back in the morning.
The second round will resume at 07:00 BST on Saturday, with 14 groups still to finish.
After the flood
Foul weather was forecast for the morning but it was even worse than expected, with downpours leaving parts of the course underwater.
But after sterling work by the St Andrews ground staff, who were aided by the sandy Old Course's natural drainage system, the sun broke through and low scoring was suddenly a possibility.
Overnight leader Dustin Johnson continued where he left off on Thursday, going out in 33. Gusts made putting more and more difficult as the day progressed and Johnson bogeyed the par-three 11th, but will be pleased with his day's work.
Playing partner Spieth, usually so cool, was visibly frustrated by the difficult conditions and the Masters and US Open champion was level for his round with five to play, having mixed three birdies with three bogeys.
Willett staying grounded, Rose keeps blooming
Yorkshire's Willett, who signed for a 66 on Thursday, made three birdies in an outward 33 before dropping shots at 15 and 17 in a stiffening wind.
However, the 27-year-old rolled in an eight-foot birdie putt at the last to post an imposing halfway target.
"Seeing my name on top of the leaderboard is something I'm going to have to embrace, or there's no point being there," said Willett, a former world number one in the amateur ranks.
Asked whether anyone had sent their congratulations, Willett replied: "I just received a text message from my mum: 'Well done on making the cut.' She always brings me straight back down to earth."
Willett's fellow Englishman Justin Rose, the world number eight, had six birdies in his round of 68 to finish on five under. Rose's compatriot and former number one Luke Donald is also in the hunt after a 70 left him four off the lead.
Sir Nick bows out in style
Rose played with Sir Nick Faldo, the last English winner of the tournament in 1992 who was appearing in his 37th and final Open.
Three-time champion Faldo, who played the final hole in the actual jumper he wore when he won his first Claret Jug at Muirfield in 1987, carded an 11-over 83 on Thursday but finished with a fine round of 71.
"Yesterday was no fun and I wasn't interested in playing today but my kids told me I would regret it if I didn't," he told BBC Sport.
"It was all about standing on the bridge and I wanted to bust out my old jumper. It would have been stupid to miss that."
Scott out for redemption
World number 11 Scott blew a four-shot lead in the final round of the 2012 Open at Lytham, eventually finishing second behind Ernie Els.
The Australian won the Masters the following year and was also in contention at the last two Opens, in which he had top-five finishes.
"I definitely let that one slip [at Lytham] and I've had a couple of good looks since then," said the 34-year-old, who is playing in his 16th Open.
"You know what? I think I'm playing with a bit of a chip on my shoulder."
Amateur hour, again
Ireland's Paul Dunne equalled the best ever halfway score by an amateur after a second successive 69 propelled him to six under par.
But he still has plenty of competition for the coveted Silver Medal, with Frenchman Romain Langasque (-4 after 13) Americans Jordan Niebrugge (-4) and Oliver Schniederjans (-1) and England's Ashley Chesters (-1) all making the cut.
Going, going, gone?
Others set to miss the projected cut of level par include England's Ian Poulter (+3) and five-time champion Tom Watson (+12).
Watson, 65, finished his round just before the hooter sounded to signal the suspension of play but plenty of diehard fans remained to salute him as he posed on the Swilcan Bridge in near-darkness.
Watson's 38th Open ended in a far-from-vintage round of 80 but he will be remembered as one of the greatest players in the tournament's long history.
"There's just so much joy in walking up that hole. I don't know how to put it into any other words. It's all joy.
"There's no reason to be sad. I played a game for a living, and I played it pretty well over time."
Two-time Masters champion Bubba Watson is level par after 15 and will have to complete his second round on Saturday morning.
When the wind blows...
As many as 42 players will conclude their second rounds on Saturday morning before a scheduled third round tee-off time of 11:00 BST, and the challenge throughout the day looks set to be strong winds.
The strength of the gusts could well offer the R&A a dilemma as to whether a suspension is needed but the forecast does not highlight any spell where the elements may be calmer.