Captain Marvan Atapattu believes Sri Lanka could have beaten England if the rain had not cut short their match at the Rose Bowl.
His side were 95-5 after 24 overs in reply to England's 251-7 when bad weather forced play to be abandoned.
"I would rather have played the full 50 overs and lost than finish like we did today," said Atapattu.
"We fancied our chances as we bat down to 11. Nuwan Zoysa won a match against Australia in Colombo."
Sri Lanka dropped several crucial chances, including centurion Andrew Flintoff when he had just got off the mark, and again on Sunday when he had made 25.
Atapattu admitted their fielding "wasn't our best - nowhere like in the recent past.
"Unfortunately it happened to be in a very crucial game."
"Walking onto the field today I thought 220 would be a chasable amount but today I saw a significant change in the wicket.
"It didn't do as much when we bowled as it did initially for the Englishmen."
Asked about England's chances against Australia in the semi-finals, he replied: "No team is unbeatable as far as I know.
"In one-day cricket whichever team plays well on the day will come up trumps."