Afridi again led the way with four wickets - taking his tally to 21 for the tournament - as West Indies were bowled out for a paltry 112, a target Mohammad Hafeez and Kamran Akmal chased down inside 21 overs.
It was a convincing success, on Pakistan's national day, that has further underlined their chances of winning the tournament for a second time.
And while Afridi had tipped his side to reach the last four before the tournament, he was unwilling to entertain thoughts of Pakistan going further just yet.
• Dhoni banks on cheers of 40,000 Indian fans against Australia
• Ponting will rewind to 2003 as he gets ready for the Indian spinners
• Captain Ponting has the Australian team's support, says Mike Hussey
• A dreaded feeling for the casual onlooker to the India-Australia game
"I'm very happy because before this competition I told my friends and the nation that with this team I wanted to play in the semi-finals," he said in an interview shown on Sky Sports 1.
"There will now be more expectations to go on.
"But I am just thinking game by game. The only thing we can do is give 110 per cent.
"Every team from now will come harder and harder.
"We will just keep making plans for each team and try and stick to those."
Pakistan face a tough task in the last four where they will meet the winner of today's match between India, the tournament favourites, and Australia, the three-time defending champions.
Pakistan beat Australia in their previous game, to end the Antipodeans' 34-game unbeaten World Cup run and top Group A, to underline their spoilers' potential after coming into the tournament as outsiders.
Afridi put his team's slightly unexpected run to the last four down to the planning of Waqar Younis, the coach.
"On each and every game we make plans with the coach and we stick to those plans," he said.
"Everyone has done a great job, especially the bowlers from the first game.
"This was a great performance, this is the best gift to give to my nation."
Darren Sammy, the West Indies captain, was left to reflect on the meekest of exits from the tournament, but believes a youthful side will learn from their disappointment.
"We definitely did not get enough runs," he said.
"They bowled well at us and we didn't counteract, hence we were bowled out cheaply. Throughout tournament we have been losing wickets to spin and today was no exception."
He added: "We look at our squad and have a number of players under the age of 27 which augers well for us.
"We have a few youngsters that should be around for next World Cup. We didn't play to our full potential at all in this tournament. When we do that we can beat any team on our day."