After captain William Porterfield won the toss and provided Ireland's only resistance at the crease, scoring his first World Cup century (107), Pakistan replied methodically at Adelaide Oval, scoring its first 100 runs without loss as openers Sarfraz Ahmed (101 not out) and Ahmed Shehzad (63) found gaps in the Irish field placements.
Sarfraz's century was Pakistan's first of the tournament, leading his team to 241-3 in 46.1 overs. Umar Akmal (20 not out) spent much of his time in the final overs blocking shots in order to give Sarfraz the strike and a chance to reach 100.
The win moves Pakistan, which lost its first two matches before winning its next four, into a quarterfinal match at the same Adelaide ground on Friday against four-time champion Australia.
Left-arm fast bowler Wahab Riaz took 3-54 and Sohail Khan had 2-44 to lead the Pakistan bowlers. It was Pakistan's first win at the tournament while batting second.
It was a disappointing end to the tournament for second-tier team Ireland, which won three of six matches, including victories over higher-ranked teams West Indies and Zimbabwe.
In 2007, Ireland, playing in its first World Cup, upset Pakistan by three wickets to eliminate Pakistan from the knockout rounds.
Pakistan player Younis Khan, who played in that 2007 match but didn't get a start Sunday, said revenge wasn't in their minds. But the team wanted to win Sunday to honor the memory of former coach Bob Woolmer, who died in his hotel room the day after that loss in Kingston, Jamaica eight years ago.
Earlier, Porterfield, who was dropped on 99, was dismissed for 107 when caught by Shahid Afridi off the bowling of Khan.Ireland didn't reach 200 until the 44th over and its run rate dipped when Porterfield departed, losing 3-22 in one collapse and its last six wickets for 55 runs. Ireland also failed to establish any big partnerships, its longest being 48.
With St. Patrick's Day two days away, the Irish crowd, some wearing oversized plush green top hats, were the more vocal in the stands but had little to cheer about for most of the match. The green in Pakistan's flag and the teams both decked out in similar colors ensured that the hue was well represented around the ground.
While Ireland made no changes to its lineup for the match, Pakistan was without pace spearhead Mohammad Irfan, who has a hip injury, and dropped batsman Younis Khan. Haris Sohail and Ehsan Adil came into the starting 11.