Young opener Imam-ul-Haq, nephew of Pakistan great Inzamam-ul-Haq, smashed a hundred on debut to guide his side to a seven-wicket win in the third One-day international against Sri Lanka on Wednesday.

Seamer Hasan Ali became the quickest bowler to reach 50 ODI wickets for Pakistan as his 5/34 saw Sri Lanka bowled out for 208 in 48.2 overs at Sheikh Zayed Stadium in Abu Dhabi.

Imam, whose uncle Inzamam is now a Pakistan selector, became only the second batsman from his country and 13th overall to score a hundred on ODI debut before he finally fell for 100 off 125 balls.

The 21-year-old hit two sixes and five fours as the nominal hosts wrapped up the series with two matches to spare. Saleem Elahi was the only other Pakistani to hit a debut hundred, also against Sri Lanka at Gujranwala in 1995.

A relieved Imam returned to the crease and completed his hundred. Mohammad Hafeez remained not out on 34, scoring the winning single.

Imam said his heart was in his mouth when he was given out. “I thought I had missed a great chance of scoring a hundred,” said Imam, who was also Pakistan’s top run-scorer when they reached the 2014 Under-19 World Cup final in the United Arab Emirates.

“But Hafeez told me to wait as the ball had touched the ground, so I am lucky and proud to have scored a hundred on my debut and that too with a record.”

Pakistan hold an unassailable 3-0 lead in the five-match series after winning the first match by 83 runs in Dubai and a 32-run victory in the second in Abu Dhabi on Monday.

Sri Lanka, who suffered their ninth straight ODI defeat, were loose with the bat. Hasan, 23, was ably assisted by leg-spinner Shadab Khan (2/37) as Sri Lanka, who won the toss and batted, lost their last nine wickets for only 106 runs.

Sri Lanka skipper Upul Tharanga (61) and Dickwella (18) put on 59 for the first wicket, but from 102/1 in the 26th over their innings was derailed by Pakistan’s bowlers. Shadab, Man-of-the-match for his 52 not out and 3/47 in the second game on Monday, had Dinesh Chandimal (19) leg-before and Tharanga caught in the deep.

The previous record was held by legendary paceman Waqar Younis, who took 27 ODIs to reach the mark. Sri Lankan spinner Ajantha Mendis holds the overall record of 19 matches.