Pakistan batting coach Grant Flower says World Cup victory over England has lifted a "huge weight" ahead of Friday's clash with Sri Lanka.

Heading into the tournament in poor form, Pakistan then suffered a dismal seven-wicket defeat to West Indies in their opening match after being bowled out for 105..

But after responding in style with a 14-run upset win over England in which they scored 348 for eight, the 1992 champions are now looking to build on that morale-boosting triumph when they take on Sri Lanka in Bristol.

"I definitely do sense quite a bit of confidence," former Zimbabwe all-rounder Flower told a pre-match press conference, according to icc-cricket.com.

"Since we have won, it took off a lot of the pressure definitely, having gone through those string of defeats.

"Psychologically, that lifts a huge weight from their shoulders, and to score 350 against a very good England attack, the guys are relieved.

"We didn't adapt well to the conditions against West Indies. Technically, we were a bit poor on the day and I think there were a lot of nerves being the first World Cup match, definitely.

"Then the guys got over that against England and they showed their proper skills and it was a true test of character. They came through with flying colours in the second game."

Pakistan's preparations for the World Cup saw them suffer a 4-0 series whitewash against England before being beaten by Afghanistan in what proved to be their final warm-up match.

With Sri Lanka starting the competition with a win and a loss, Flower is predicting an entertaining encounter at Bristol County Ground, although heavy downpours are forecast.

"You have always got to be respectful, and they have got good bowlers," continued Flower.

"I have just come out of a batting meeting to see their skills and it should be a good game. Hopefully the weather stays away, it is a bit poor, the forecast.

"The guys are fully focused and they know what to expect."

Sri Lanka, who bounced back from a thrashing to New Zealand by recovering from a batting collapse to edge past Afghanistan, have never beaten Pakistan in a World Cup match.

Captain Dimuth Karunaratne has called on his batting line-up to start producing in order to end that record.

"I saw a good team spirit (against Afghanistan), and the fielding unit and the bowling unit did a good job," he said.

"Now the batting line-up, they have to put their hands up and do the job.

"This is a good flat wicket, and if you take the past matches, everyone's scoring more than 300 runs.

"If you can put on 300, our bowlers can defend it, I'm pretty sure of that.

"I think we don't want to change many things, I think this is our best batting line-up we can produce.

"Pakistan is an unpredictable team, but I think we have a bit of confidence so we will be trying to give our best."