Captain Mushfiqur Rahim, with a Test cap at Lord's behind him, led the successful chase with a masterly match-winning knock of 46 after Sakib Al Hasan's four-wicket haul for 34 runs restricted Pakistan to a modest 170.

The victory on Wednesday meant the high-flying Bangladesh youths, who beat New Zealand by three wickets in the opening match, advanced into the quarterfinals for the first time after being eliminated from the group stages in the previous four Youth World Cups.

Mushfiqur Rahim's boys will now face lowly Uganda today at the Sinhalese Sports Club Ground, and a victory will land them as Group A winners.

England also sneaked into the Super League with a nail biting four-run win over Ireland and their win places them into the quarterfinals from Group D, along with Zimbabwe, and their meeting on Friday will decide which of them meet Bangladesh in the last eight.

The Bangladesh-Pakistan match however was a study of striking contrast. While Pakistan collapsed after a fairly sound start, Bangladesh produced a class apart in Mushfiq after a horrible start that saw the junior Tigers at one stage wobbling at 88-4.

Sent into bat, Pakistan raced to 66 without loss before a four-pronged left-arm spin attack led by man-of-the-match Sakib effectively dashed stroke-happy Pakistanis' hopes of a big score. Sakib started the carnage by removing Nasir Jamshed (37), who was caught at point by Nabil Samad, and then picked up three more wickets as Pakistan slipped to 107-4 from where they had never recovered.

Number five batsman Ali Asad, who top scored with 70-ball 38, tried to turn the tide but Sohrawardi Shuvo and first-match hero Mehrab Hossain Jr shared four wickets besides Nabil's one to bowl Pakistan out in 43.1 overs.

Bangladesh, in their chase, tumbled like they did in the first game against New Zealand with the vaunted top-order perishing one after another.

Left-handed opener Tamim Iqbal (18), Raqibul Hasan (27) and Sakib (25) departed playing ambitious shots before Mushfiqur strode in to show how to play and score on a non-responsive wicket for a batsman.

The right-hander's composed 55-ball 46 contained seven fours. He also tied the scores with a majestic six when he flicked the ball off his pads. But he was out next ball while trying to go over the mid-wicket fielder. However, Bangladesh reached the target 171-6 in only 34.5 overs.

Chief selector Faruque Ahmed, who is now in Sri Lanka with the future stars, highly praised Mushfiqur's innings although he was not satisfied with the top-order batting in two matches.

"Mushfiq played a real captain's knock. It was also a composed and class knock which guided the team to a comfortable victory after the bowlers had set the platform. But I'm really disappointed with the top-order that failed for a second time," Faruque told the Daily Star Sport over phone from Colombo.

The former national captain, however, was excited with the fact that Bangladesh for the first time qualified in the upper stage of the competition.

"It was not unexpected given their success in the last seven months but no doubt it was a big achievement for an extraordinary batch which has the ability to win matches consistently," said an elated Faruque.

"The boys came into this tournament as one of the favourites and so far they have proved that it was not a fluke and I can only assure you that boys are ready for further challenges. They have the rare quality to avoid complacency after winning any matches," he added.

"We are not thinking about our quarterfinal match rather we are looking forward to beat Uganda in the last group match tomorrow to maintain the winning run," he said.

Mansoor Rana, the Pakistan coach, praised Bangladeshi spinners but he also blamed his batsmen for playing too many shots.

"Their four spinners bowled well, but obviously I would blame my whole batting side for playing unnecessary shots. Sometimes we try to be perfectionists and that is wrong. The boys will go away, think about this, and try to put things right against New Zealand, which we know is now a vital game," said Rana to Cricinfo.