Anirban Lahiri: Rory McIlroy's recovery highlight of second day's play

USA’s Jordan Spieth plays a shot on the 18th hole in a practice round ahead of the British Open in Southport on Wednesday

The 35-year-old from Johannesburg got off to a flying start with birdies on the first, third and fifth before picking up further shots on the 10th and 17th to get back to level par for the tournament. He's keen to return to form, remembering how he revelled in the 2014 season when he won four top tournaments, including the Open at Hoylake, and the US PGA title at Valhalla, which was his fourth major victory in three years.

Martin Kaymer was approaching the sixth tee during a practice round at Royal Birkdale when he told his playing partners that he was calling it a day.

The duo were eventually joined by fellow American Matt Kuchar, who matched their efforts later in the afternoon with a 65 of his own.

After bogeying the 13th and 15th, McIlroy calmly rolled in an eight-foot birdie putt at the 17th.

"I set myself a target of being in a better position today than I was yesterday". Very simple, but obviously quite effective over the past 27 holes, and I feel like I have. So things are in check. And the birdie chances I had early on I didn't make them. This is the 12th time he has been atop the leaderboard at the end of a round in a major, including the final rounds of the Masters and U.S. Open that he won in 2015.

McIlroy hasn't missed the cut at consecutive majors since 2010 (Masters, U.S. Open) and is taking confidence from winning the Deutsche Bank Championship in Boston in September a year ago after being 4 over through three holes.

Spieth, though, defied a torrential downpour - which led to ground staff needing nearly half an hour to sponge the rain-soaked greens - to assume control with his eagle on the par-5 15th. But having said that, digging myself out of the run of bogeys on the back nine, is something I am proud of. I'm just waiting for that round or that moment or that week where it sort of clicks and I'll be off and running.

"I feel like I can hit the ball in the fairway, and from there I can hit the ball on the green", McIlroy said. He opened this one with an even-par 70, then added a 72 in blustery conditions in the second round.

As the final groups headed out on to the course, the American pair enjoyed a two-shot lead over compatriot Justin Thomas and the English duo of Ian Poulter and Richard Bland, with Welshman Stuart Manley part of a group on two under on his Open debut.

South African Ernie Els and BMW PGA champion Alex Noren are among those on two under, three back, alongside World No 2 Hideki Matsuyama.

Northern Ireland's Rory McIlroy waits for a sign to be moved so he can play his shot in the rough on the 15th hole during the second round of the British Open Golf Championship at Royal Birkdale, Southport, Friday July 21, 2017.

"I am just trying to remember the last 12 holes and scrub the rest out of my mind", McIlroy said. There were some [Open] Championships where I really played well and others where I just kind of hung in there like a horse race.

There were wet and windy conditions as The Open Championship kicked off at Royal Birkdale on Thursday. The Swede lies four shots back alongside Australian Jason Day.

Poulter, runner-up in the 2008 Open on this course, rattled in four birdies and made only one bogey as rain and strong crosswinds caused problems for the early starters.