The 10-team competition had just begun to look a little predictable halfway through the group stage with champions Australia joining the top three ranked ODI teams seemingly with a foot in the knockout stages.
Sri Lanka's old warhorse Lasith Malinga then conjured up a four-wicket masterclass as the 1996 champions stunned the hosts in a low-scoring thriller to shake up the tournament, jeopardising England's semi-final prospects in the process.
The hosts are still third with eight points from six games but face Australia, India and New Zealand -- teams England have not beaten in the World Cup since 1992 -- in their last three group matches.
"It's a great win for Sri Lanka, but also for the World Cup and it opens things up a little," Jayawardene wrote in a column for the International Cricket Council (ICC).
"The top four so far have a lot of matches against each other coming up, so they will inevitably drop some points.
"You look at New Zealand, Australia and England who all have to play each other which does make it interesting."
The upset should reinvigorate not only Sri Lanka but also Bangladesh and West Indies in their bid to finish among the top four for a place in the semi-finals, the former test batsman added.
Sri Lanka have looked rather inconsistent in the tournament with only two wins from six matches, even if two of their matches were washed out.
Jayawardene is optimistic, however, that the former champions, who also reached the final in 2007 and 2011, could progress.
"I've always been convinced that Sri Lanka step up their game at World Cups," he wrote. "They have the ability and they have the skill. This game should give them the confidence."
(Reporting by Amlan Chakraborty; editing by Nick Mulvenney)
