Spinner of the leg Rehan Ahmed picked up three wickets within the penultimate turn to win by 15 runs on the island of Antigua.
It’s the first time England has made it to the semi-finals in the U19 World Cup since winning the tournament in 1998.
They will take on one of Australia or India on February 5th.
England was at 231/6 in just 47 overs, following a half-century by George Thomas (50), George Bell (56), and Alex Horton (53).
They struggled at 136-6 when Bell and Horton created 95 runs to give England an acceptable score to protect.
During the chase, Afghanistan appeared to be in control with 94-1, but three wickets quickly in 12 balls dragged their opponents back.
However, the game was turned upside down two times in the final four innings.
At 188-6, Afghanistan needed 43 from 24 balls before James Sales began the fourth-to-last over.
However, the England pacer bowled two no-balls in the first over and then surrendered 20 runs, completely changing the pace.
But England rallied. Joshua Boyden conceded just four runs in the next over before Ahmed threw the final six balls into the bowl.
After amazing shots, the England spinner was a match-winner as he hit with the first, fourth, and fifth delivery to leave Afghanistan nine wickets behind and with too large of mountains to scale.
“I do not believe I was expecting to see it get so close at the end of the game the way it was going however, I’m very grateful to the guys,” England captain Tom Prest declared via ESPN Cricinfo.
“I am unable to believe it.
