South Africa bowled the reigning champions out for 156, before easing to an eight-wicket victory after posting 160/2 in just 25.4 overs.
The defeat was the latest in a long line of disappointments at the tournament, with England failing miserably to live up to their tag as one of the bookmakers’ favourites to lift the trophy.
A record of one win in five games has left punters scratching their heads, particularly in emerging betting jurisdictions such as the Middle East.
Several cricket betting sites in Arab countries fielded a flurry of wagers on England in the run-up to the World Cup, forcing them to significantly cut their odds in the outright market.
However, England have proved to be an ally for the bookies, with a victory over Bangladesh all they have to show from their efforts after five matches.
More worryingly, the manner of their performances against New Zealand, Afghanistan, South Africa and Sri Lanka has left many sports bettors scratching their heads.
In his press conference after the Sri Lanka game, Buttler admitted that his team’s inability to compete with their rivals has left him perplexed.
"We're a really good team – we’ve done a lot of really good things in the recent past in white-ball cricket and 50-over cricket,” Buttler said.
"You get on the plane with high hopes and a belief we can challenge for the title so to sit here now after the three weeks which have been is a shock. It's a shock to everyone.
"I'll go back to the changing room and look at the players sat there and think, 'how have we got ourselves into this position with the talent and the skill that's in the room?'
“But it's the position we're in, it's the reality of what's happened over the last three weeks. It's a huge low point.”
Having arrived in India as the first ever men’s team to hold the ODI and T20 World Cup titles at the same time, England’s demise has caught many people by surprise.
However, their failure to rejig what has undoubtedly been a hugely successful team has eventually caught up with them. The top teams keep evolving and England have not done that.
Every player selected against Sri Lanka was aged 30 or over – the first time this has ever happened in the 791 one-day internationals England have played.
They made a reasonable start against Sri Lanka, with their openers making 45 in just 6.3 overs. Things quickly went downhill from there as five wickets fell in the next nine overs.
In stark contrast to their displays in recent limited overs tournaments, England’s players were guilty of being too cautious. David Willey’s solitary six during their innings was testament to their inability to take the game to Sri Lanka.
While Ben Stokes did his best to drag England out of their slump, a knock of 43 runs in 73 balls demonstrated that even his heroics were not at their usual level.
England were equally unimpressive with the ball, and their inability to stem the flow of singles ultimately allowed Sri Lanka to pass their target easily.
Buttler insisted the players knew they had to make things happen if they wanted to retain the title and dismissed the idea they had taken things for granted during the tournament.
“In any sport, you can’t protect anything, you have to go and create something new,” Buttler added. “We’ve touched on experience and having banked stuff before but something we spoke about a lot as a team is that you have to go and create it again.
“You can’t rest of your laurels or just to protect an image or protect something as a team. That’s why at the very beginning of the tournament, I said we weren’t here to defend our title, we were here to start something new and win something.
“Obviously, we’re falling a long way short of that at the moment but, as players, we didn’t take anything for granted or just think it’ll be alright on the night. You don’t get to the level like this by thinking like that.”