London - Jonny Bairstow rode his luck to again rescue England from a top-order collapse with a century on the first day of the third Test against Sri Lanka at Lord's on Thursday.
At stumps, England were 279 for six, having been 84 for four when Bairstow (107 not out) came to the crease.
It had been a similar story when Bairstow revived England from the depths of 83 for five in the first Test with a superb 140 on his Headingley home ground in a match England eventually won by an innings and 88 runs.
Rather than scoring a maiden Test century at Lord's, Bairstow should have been out for 11 on Thursday when he clipped Nuwan Pradeep firmly off his pads straight to mid-wicket only for Shaminda Eranga to drop the catch.
The Yorkshireman had another break when Eranga, selected despite having his action reported in England's series-clinching nine-wicket win in the second Test at the Riverside, reviewed a rejected lbw appeal when the batsman had made 56.
Replays showed the ball hitting leg stump, but not enough, according to the Decision Review System, to overturn Indian umpire S Ravi's original not out decision.
Apart from Bairstow, only England captain Alastair Cook (85), who won the toss in sunny conditions ideal for batting, passed fifty on Thursday, with Chris Woakes 23 not out at stumps.
Sri Lanka performed admirably with the ball, albeit they were again sloppy in the field, on a good pitch where there was a touch of seam movement.
Suranga Lakmal and Nuwan Pradeep shared four wickets while impressive left-arm spinner Rangana Herath rook an economical two for 45 in 21 overs.
England had already won this three-Test series at 2-0 up.
Cook insisted in the build-up to this match that England were determined to correct their habit of losing 'dead' Tests in series they'd already won following heavy defeats at the end of victorious campaigns at home to Australia in 2015 and away to South Africa earlier this year.
Cook, presented with a commemorative bat before play to mark his achievement in becoming the first England batsman to score 10,000 Test runs, a landmark he reached at the Riverside, and fellow opener Alex Hales compiled a fifty stand in 74 balls.
But Herath struck with just his fourth ball he had Hales (18), slogging across the line of a ball that turned, caught by Sri Lanka captain Angelo Mathews at slip.
By his own admission, Nick Compton was playing for his Test place.
But England's number three, on his Middlesex home ground, fell for one when he was caught behind off a gentle Lakmal away-swinger.
Lakmal struck again when he had Joe Root (three) lbw, hitting across the line.
Pradeep got in on the act by bowling James Vince for 10 and England were now 84 for four -- the fifth time in their last seven Test innings they had lost four wickets before reaching 100.
Left-handed opener Cook was closing in on his 29th Test century when, shortly before tea, he was plumb lbw to Pradeep, bowling from around the wicket.
Cook faced 173 balls, including nine fours.
Moeen Ali, fresh from his Test-best 155 not out at the Riverside, followed Hales in falling to the Herath/Mathews combination for 25.
Bairstow, strong off his pads and on the drive, cut Pradeep for four to go to 94.
He then equalled his previous Test-best at Lord's of 95, made against South Africa in 2012 before a single off Herath saw him to a 160-ball century.