Joe Root celebrates after reaching his century. (Getty Images)
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 5 at stumps on the first day of the first Test after they'd been struggling at 74 for 3 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 fifty in 21 Test innings.
Moeen Ali (48), one of three debutants in a new-look England side, had previously helped Root steady the ship during a fifth-wicket stand of 89.
Sri Lanka captain Angelo Mathews won the toss and elected to field against an England team playing their first Test since their 5-0 Ashes drubbing in Australia.
Although the sunny blue skies above Lord's suggested ideal batting conditions, the pitch was a greener-looking one than usually associated with the 'home of cricket' at this time of year.
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 allrounder 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 1 became 22 for 2 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, Mark Waugh to play 100 consecutive Tests, exited for 17 when the left-hander bottom-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.
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 3 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 fifty.
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 found his form in slog-sweeping Herath for a six.
Together with Root he prevented any further loss of wickets before tea as England reached the interval on 195 for 4 with both batsmen unbeaten on 43.
After the resumption, Root completed his fifty but Ali fell for 48 when he drove loosely at Herath and was caught by Mahela Jayawardene at slip.
Ali batted for over two hours, striking a six and six fours, with England now 209 for 5.
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, went to fifty when he cover-drove Pradeep, bowling with the new ball, for his seventh four in 81 balls.
Root drove Kulasekara down the ground to go to 96 before a three off Herath saw him to his third hundred in 16 Tests off 183 balls including eight fours.