Hyderabad/UNI: Mohammad Rizwan and Abdullah Shafique smashed glorious centuries to pull off the biggest-ever chase in ICC Men's Cricket World Cup history to beat Sri Lanka in an enthralling game at Rajiv Gandhi International Stadium here on Tuesday.

It required a special effort from Pakistan to chase a score in excess of 340 in their ODI history. Their previous highest World Cup chase was 263.

For this to happen, Shafique and Rizwan set things up with a magnificent 176 runs partnership for the third wicket, and finished the game in Pakistan's favour with six wickets in hand and 10 balls to spare.

This was the first time in men’s Cricket World Cup history that four centuries have been hit in the same match, with Pakistan coming out on top in a high-scoring thriller.

Pakistan’s chase got off to not their likings after Imam-ul-Haq (1) and Babar Azam (10) walked back in the first powerplay, with Dilshan Madushanka taking both wickets.

But Pakistan steadied the ship and built a platform, with Shafique cracking his maiden ODI century (113) off 103 balls, which was studded with 13 boundaries.

Rizwan was even more robust of the two as he steered Pakistan to the record-making chase in their cricketing history at the world cup, before he went down with cramps at one stage. Deservedly, the winning runs should have come from his blade and did it after scoring an unbeaten 131 off 121 balls.

To lose in such a manner will be a crushing blow to a Sri Lankan side who suffered a first-up defeat at the hands of South Africa.

Pakistan remained unbeaten at the Cricket World Cup, with this extraordinary victory following their impressive first-up win against the Netherlands.

Earlier, Kusal Mendis and Sadeera Samarawickrama helped build a formidable total of 344/9 as both stroked excellent centuries that left Pakistan needing a record chase.

Sri Lanka began poorly by losing Kusal Perera left without troubling the scoreboard – the second duck for a Lankan opener in the tournament.

Hasan Ali got Perera with Pakistan’s opening bowlers looking dangerous on the Hyderabad wicket. But Mendis blunted the Pakistani threat, smashing 20 boundaries including six maximums in his sensational 77-ball 122 to put his side on course for a big total.

Pathum Nissanka (51) batted well at the other end, before Samarawickrama joined Mendis out in the middle.

And it was Samarawickrama who steadied the ship as Hasan returned to pick up the key wicket of Mendis and Charith Asalanka (1) in his next over to expose Sri Lanka’s lower to middle order.

With Samarawickrama helping take his side beyond a score of 300, Sri Lanka were looking to finish big and set Pakistan’s batting line-up a big challenge.

Samarawickrama reached his century as Sri Lanka pushed in the death overs, but became Hasan's fourth wicket as he looked to play a reverse pull to find a gap in the outfield.

Hasan finished with figures of 4/71, and Pakistan did well to keep the scoring in check late on as wickets fell at useful and regular intervals.

Sri Lanka suffered a first-up defeat at the hands of South Africa, but were boosted by the inclusion of star spinner Maheesh Theekshana for this match after he missed the loss to the Proteas with a hamstring injury.

Pakistan are looking to remain unbeaten at the Cricket World Cup, following their impressive victory first-up against the Netherlands and also made one change to their XI for the contest, with opener Abdullah Shafique coming in for Fakhar Zaman.

Brief scores: Sri Lanka 344/9 in 50 overs (Kusal Mendis 122, Sadeera Samarawickrama 108; Hasan Ali 4/71) lost to Pakistan 345/4 in 18.2 overs (Mohammad Rizwan 131*, Abdullah Shafique 113; Dilshan Madushanka 2/60) by six wickets