Sri Lanka captain Angelo Mathews has described his side's World Cup exit at the quarter-final stage as their "worst performance" of the tournament.

The team struggled with the bat as they could only muster 133 runs before getting bowled out by South Africa at the Sydney Cricket Ground.

Mathews believes that nerves contributed to their downfall as the Proteas grabbed a nine-wicket win, which is their first knockout triumph ever in the tournament.

"There were no demons on this track, we thought we could get at least 250 and give our bowlers a chance, but we didn't bat well," BBC Sport quotes Mathews as saying. "Maybe it was nerves, we didn't go for our shots and it's easily our worst performance we have done in the World Cup and it happened to be in the quarter-final.

"We all knew South Africa had a good bowling attack, but we just did not bat well from ball one. I thought we were a bit nervous, but that's the way it goes. Anything can happen in the quarter-finals and all the teams left are capable of winning it."

Bangladesh, India, Australia, Pakistan, New Zealand and the West Indies are all fighting for a semi-final spot.