London - Joe Root's second hundred in as many Lord's Tests was the cornerstone of England's recovery on the first day of their series opener with Sri Lanka on Thursday.
Root's 102 not out helped take England to 344 for five at stumps on the first day of the first Test after they'd been struggling at 74 for three when the 23-year-old Yorkshireman walked out to bat.
Root, who made a Test-best 180 against Australia at Lord's last year, was well supported by Matt Prior (76 not out) in a so-far unbroken sixth-wicket stand of 135.
However, recalled wicketkeeper Prior was fortunate not be out for a second-ball duck before completing just his second 50 in 21 Test innings.
Moeen Ali (48), one of three debutants in a new-look England side following their 5-0 Ashes drubbing in Australia, had previously helped Root steady the ship during a fifth-wicket stand of 89.
"It's a very slow wicket and hard to time when the ball goes softer," Root told Sky Sports. "It was a day when you had to scrap.
"There's nothing that beats Test cricket and the challenge of scoring runs in the first Test of the summer after the winter we had was something that I relished."
Root, criticised for not playing forward enough in Australia, added: "Getting forward is something that I'm working on and want to develop. I worked hard on that today."
Things initially went well for Sri Lanka after captain Angelo Mathews won the toss and elected to field.
Although sunny blue skies above suggested ideal batting conditions, the pitch was a greener-looking one than usually associated with Lord's at this time of year.- Early double strike -
Mathews's decision yielded a quick reward as England lost both their openers inside the first half hour.
Australia-born Sam Robson, one of England's newcomers along with Ali and all-rounder Chris Jordan, fell for one on his Middlesex home ground when drawn forward into edging a full-length Nuwan Pradeep delivery that was well caught by diving wicketkeeper Prasanna Jayawardene.
And 14 for one became 22 for two when England captain Alastair Cook, who in this match became only the fourth man after India's Sunil Gavaskar and the Australian duo of Allan Border and Mark Waugh to play 100 consecutive Tests, exited for 17 when he edged an intended cut off Nuwan Kulasekara into his stumps.
Ian Bell, the only other experienced batsman in a revamped top order, eased first-change Shaminda Eranga through the covers for four.
Gary Ballance looked less assured and the Zimbabwe-born left-hander's innings ended when he was caught behind off Pradeep for 23.
England had struggled to 98 for three at lunch but Bell was unbeaten on 41 and looking in excellent touch in his 99th Test.
Shortly after lunch, he drove left-arm spinner Rangana Herath for six to go to a 69-ball 50.
But he was out soon afterwards when, hitting across the line, he was lbw to Eranga although Sri Lanka had to first challenge Australian umpire Paul Reiffel's original not out decision .
Ali began cautiously but the left-hander and Root were both unbeaten on 43 at tea.
Root subsequently completed his fifty but Ali fell just short when he drove loosely at Herath and was caught by Mahela Jayawardene at slip.
Prior, dropped during the Ashes, had still to score on Thursday when struck on the back leg by Herath.
Sri Lanka appealed for lbw but Reiffel ruled in the batsman's favour and, despite a review, the 'umpire's call' stood after replays indicated the ball, which would have hit the stumps, had pitched fractionally outside off stump.
Meanwhile, the initially watchful Root cut and cover-drove Eranga for two well-struck boundaries.
Prior, who marked his Test debut with a hundred at Lord's against the West Indies in 2007, reached 50 when he cover-drove Pradeep, bowling with the new ball, for his seventh four.
Root, obliged to be more vigilant, drove Kulasekara down the ground for just his eighth boundary to go to 96 before then reaching his third hundred in 16 Tests off 183 balls with three off Herath.