Sri Lanka confidently finished their chase as Pathum Nissanka (77 off 83 balls) and Sadeera Samarawickrama (65 off 54 balls) led the process with an unbroken 137-run stand for the third wicket.
England's reign as the 50-over World Cup champion sunk into serious jeopardy as resolute fifties by Pathum Nissanka and Sadeera Samarawickrama along with a set of on-the-money bowlers spurred tenacious Sri Lanka to an eight-wicket victory in Bengaluru on Thursday. (Scorecard | As It Happened | Points Table | Full Coverage)
England, opting to bat first, suffered a baffling batting implosion and were bundled out for a paltry 156, courtesy of the five wickets shared among themselves by comeback man Angelo Mathews (2/14) and impressive Lahiru Kumara (3/35).
Despite losing a couple of early wickets, Sri Lanka confidently finished their chase as Nissanka (77 off 83 balls) and Samarawickrama (65 off 54 balls) led the process with an unbroken 137-run stand for the third wicket.
With just two points from five matches, England retain a mere theoretical chance to make it to the semifinals, while the Islanders, who now have four points, can eye a few stronger outings in the remaining four matches.
England might have hoped for a miracle when they dismissed opener Kusal Perera and Lankan captain Kusal Mendis through left-arm pacer David Willey to reduce their opponents to 23 for 2.
But Nissanka and Samarawickrama, two of SL's best ODI batters this year, combined to produce a solid partnership to ease Lanka's nerves.
The right-handers are capable of elegance but with a victory very much in need the pair traded flair for compactness for a good part of their alliance.
Flashes of their natural batsmanship, though, were there. Samarawickrama delectably drove Wiley through the covers, while Nissanka waltzed down the track and smoked leg-spinner Adil Rashid over long-on for a huge six.
Nissanka brought up his fifty, his fourth in the tournament, with a flowing cover drive off pacer Mark Wood and Samarawickrama reached his second half-century of this edition with a wristy single to mid-wicket off Chris Woakes.
But otherwise, the Lankans batted within themselves and gathered runs in a determined fashion to keep England bowlers at bay.
And England lacked determination on the day. It was just a matter of a couple of batsmen sticking out in the middle for the Three Lions to reach a far better and competitive total.
But none barring Ben Stokes (43) and Dawid Malan (28) did not even remotely attempt to bat with purpose for a team that was playing in a must-win match.
There was a bit of spongy bounce on the M Chinnaswamy Stadium deck and the Lankan bowlers were accurate but the shambolic way in which the England batsmen played could not be shielded.
Opener Dawid Malan who milked 45 runs with his partner Jonny Bairstow, could be excused though.
Mathews, an injury replacement for pacer Matheesha Pathirana, put him in two minds with a delivery that bounced from the length just enough to take an edge off his bat to Mendis behind the stumps.
However, Malan during his 25-ball 28 showed that the pitch is not a hard one to bat on while essaying some gorgeous drives through the off-side.
Unfortunately, several subsequent batters were culpable of playing poor cricket.
Joe Root got run out while taking off for a non-existent single, captain Jos Buttler made an expansive drive outside the off-stump off Kumara to get caught behind and Bairstow never timed the pull-off Kasun Rajitha to find Dhananjaya de Silva at mid-on.
Liam Livingstone played the wrong line off Kumara to get trapped leg-before. Moeen Ali went for a cut-off Mathews when there was no width on offer, and Kusal Perera snaffled the simple offering at the point.
These were batsmen who were expected to lead England's batting charge and they failed to respond.
Stokes did try on his own. He had the assistance of fortune as well when Samarawickrama floored a tough chance at point off Kumara when the all-rounder was on 12. England were 86 for 5 then.
The left-hander played some archetypal power-packed shots through either side of the wicket, but the day was not made for a one-man show.
His dismissal, caught by substitute Dushan Hemantha, at deep of Kumara, effectively ended England's chances of posting a challenging total.
Rashid's comical run out while backing up too far could be taken as a symbol of England's drudges with the bat on the day.
But the inept batting display of England should not rob the Lankan bowlers of the just credit.
Kumara tends to be all over the place but when he hits his lengths correctly, the right-arm pacer is a different beast who can hustle the batters.
And hustled England were indeed on the day by a vastly superior Lankan side.