To get to the semis, Charles Grasty's group beat a bigger and more athletic King squad.
"Box out, box out, and box out," junior guard Matt Penecale said. "That's what we talked about before the game. We had to keep them off the glass."
Senior guard Anthony Lee was the early catalyst. He registered 10 first-quarter points, including two three-pointers, as the Ghosts seized a 20-13 lead.
The 6-foot-3, 160-pound Lee finished with a game-high 19 points. He shot 8 for 13 from the field (2 for 4 from beyond the arc) and 1 for 1 from the foul line.
"We played smart, did a good job of protecting the ball at the beginning," said Lee, who missed the first weeks of the season because of a broken fibula suffered while he was playing quarterback in football.
Next for Abington (25-5) is a Tuesday semifinal vs. New Castle, of suburban Pittsburgh, at a neutral site and time to be announced Sunday. New Castle (29-0) ousted District 7 rival Hampton, 57-55, Saturday.
Against King, which was hurt by 19 turnovers, Penecale delivered 13 points, 5 assists, 5 boards, and 3 steals. The Ghosts were 13 for 15 from the line (9 for 11 in the second half).
The Cougars, whose front line featured 6-8 senior Jahmir Taylor (10 rebounds) and 6-6 junior Chase Rodgers (six), lost despite collecting nine offensive caroms.
Sammy Foreman, a junior guard and Division I prospect, led King (25-6) with 16 points and three steals.
"He's crafty and strong," Penecale said. "He's real quick, too, so I gave him a little space and tried to control him the best I could."
In the fourth quarter, senior Lazaros Mackrides hit a left-baseline three-pointer, his 49th three of the season, to cap a 9-2 spurt and give Abington a 49-42 lead with 31/2 minutes remaining.
Martin Luther King 13 18 9 12 - 52
Abington 20 7 13 16 - 56
MLK: Sammy Foreman 16, Jabri McCall 8, Greg Bennett 9, Chase Rodgers 10, Jahmir Taylor 9.
A: Matt Penecale 13, Amir Hinton 11, Anthony Lee 19, Lazaros Mackrides 6, Mark Bond 2, Jordan Neely 5.