With 16.8 seconds remaining, Jihad Barnes' fastbreak layup (Aflakpui was called for goaltending) put the Chargers ahead, 52-49. Carroll, instead of trying for a three-point equalizer, surprisingly settled for Aflakpui's bucket.
"They did us a favor there," Lewis said. "Once the ball went through the basket, I knew the game was over. They were out of timeouts."
Philadelphia Electrical advanced to the state semifinals for the first time.
James Suber, a 6-foot-6 senior center who has drawn interest from the likes of Maryland-Eastern Shore and Campbell, scored 16 points to lead PET, which defeated Carroll in a District 12 third-place contest last season at Ryan.
Suber added 10 rebounds, two blocked shots, two assists, and two steals. He had a huge rejection with 30 seconds remaining.
Senior guard Larenz Thurman drilled five of PET's nine three-pointers, with three coming in the second half.
Off the bench, Chargers junior guard Zakee Shakur nailed three first-half threes.
"That's the third year in a row he's played well against Carroll in this gym," Lewis said. "He might want to transfer here."
Tuesday, at a neutral site and a time to be determined, PET (19-11) will play District 12 rival Neumann-Goretti (25-4) in the semis. N-G ousted District 11 titlist Allentown Central Catholic, 60-50, Friday at Souderton.
Carroll (23-5) lost despite gathering 16 offensive rebounds. Derrick Jones, a 6-6 junior dynamo, notched 15 points, 12 rebounds, and five blocks.
Said Lewis: "He's a really good athlete. The biggest thing is to put a body on him, be physical with him, and push him outside."
Against PET's 2-3 zone, the 6-9 Aflakpui managed seven points, five rebounds, and three blocks.
Also for the Patriots, who were bidding for their first state title since 2009, sophomore reserve guard Brian Daly (12 points) drained three of his four three-pointers in the second quarter.
Phila. Electrical 14 10 16 12 - 52
Archbishop Carroll 11 12 11 17 - 51
PET: Larenz Thurman 15, Jihad Barnes 2, James Suber 16, Anthony Harris 4, Devante Truitt 6, Zakee Shakur 9.
AC: Austin Tilghman 12, Samir Taylor 5, Ernest Aflakpui 7, Derrick Jones 15, Brian Daly 12.