Gus Atkinson scored a dashing maiden century before England strengthened their grip on the second Test against Sri Lanka at Lord's on Friday.

The fast bowler's sparkling 118 helped England to 427 all out in their first innings after Joe Root's masterful 143 on Thursday equalled the England record of 33 Test hundreds held by Alastair Cook.

Sri Lanka then collapsed to 87-6 on the second day in the face of accurate England seam bowling and some loose shot-making.

But Kamindu Mendis, fresh from a fine hundred during Sri Lanka's five-wicket loss in the first Test at Old Trafford, made an admirable 74 to prevent complete humiliation before he was last man out in a total of 196.

Sri Lanka were 231 runs behind but stand-in England captain Ollie Pope did not enforce the follow-on, with the hosts 25-1 in their second innings at stumps -- an overall lead of 256.

Ben Duckett was 15 not out with Pope, having managed just three single figure scores since replacing the injured Ben Stokes as skipper, two not out after deciding against shielding himself from the new ball with a nightwatchman.

'Surreal day' for Atkinson 

But the day belonged to Atkinson as he cemented his love affair with Lord's and bolstered England's bid to take an unassailable 2-0 lead in this three-match series.

"Incredible, it was very surreal, I don't think it has sunk in yet," Atkinson told Sky Sports as he reflected on his century

"To be out there and score a hundred. I didn't ever think I would be on the Lord's honours board for batting so yeah, a pretty cool day."

He added: "I have had a pretty terrible year with Surrey for the bat so to come here and have a Test hundred is special."

The 26-year-old, whose previous highest first-class score was 91 for Surrey against a Sri Lanka Development XI in 2022, only made his Test debut against the West Indies, also at Lord's, last month.

Atkinson marked that occasion with 12 wickets (7-45 and 5-61) to etch his name on the famed Lord's dressing room honours boards reserved for bowlers who take five or more wickets in a Test innings and 10 or more in a match.

Few would have backed Atkinson to get on the equivalent board honouring those who score Test hundreds at the 'Home of Cricket' -- a feat that proved beyond such star batsmen as India's Sachin Tendulkar, West Indies' Brian Lara, Australia's Ricky Ponting and South Africa's Jacques Kallis.

Atkinson was 74 not out overnight in a Thursday stumps total of 358-7.

No 8 Atkinson carried on from where he left off, hitting two fours off Friday's first two balls, as he leg-glanced and cover-drove paceman Lahiru Kumara leg-glanced for a pair of textbook boundaries.

But to the third he was given out lbw, only for Australian umpire Paul Reiffel's decision to be reversed by a review indicating the ball would have missed leg stump.

Atkinson went to his century in storybook fashion, driving Kumara down the ground into the pavilion for another four -- his 11th in a century completed in just 103 balls and also featuring four sixes.

A spectacular innings ended spectacularly when Atkinson's mistimed pull off an Asitha Fernando bouncer was brilliantly caught by a diving Milan Rathnayake as he launched himself towards the boundary rope.

Atkinson walked off to a rousing reception, having faced just 115 balls.

Fernando ended the innings by dismissing Olly Stone to secure his place on the honours boards with a return of 5-102 in 21 overs.

Sri Lanka openers Nishan Madushka and Dimuth Karunaratne then both played on for seven before wickets continued to tumble.

But in-form left-hander Mendis, 25, again batting curiously low in the order at No 7, hit back.

He hooked three sixes off the injury-plagued Stone, playing his first Test in three years, with the last hitting an MCC member in the pavilion on the head after the ball burst through his hands as he attempted a catch.

Paramedics checked on the spectator, who appeared to be fine, before Mendis enquired about his health when returning to the pavilion after he holed out off Atkinson.