Trailing by 10 points, the struck the Bromfield School during the last, lightning round this past Sunday night.
Sharon landed a spot in the program's Eastern Mass. final four by defeating Bromfield, 455-405.
The quarter-final game against Hamilton-Wenham airs at 7 p.m. Sunday, May 15 on WGBH-2. The winner advances to the Eastern Mass. Championship, which airs May 22.
However, Bromfield very nearly beat Sharon.
Sharon led, 150 to 120, after the first, "toss up" round, where teams earned 10 points for correct answers and weren't penalized for incorrect ones.
Sharon expanded that lead to 100 points, 230 to 130, during the 90-second head-to-head round.
But, Bromfield rallied back during round three, featuring six categories of five questions each, each of greater value.
Bromfield led, 385-375, when this round ended.
"Let's hear it for both teams. What a competition!" host Billy Costa said.
"When we talk about High School Quiz Show, we promise you heated competition. And that's exactly what we have right now between the Bromfield School and Sharon High School."
Sharon's team includes senior Nishanth Iyengar, sophomores Matt Corman and Frank Zhou and freshman Siddharth Singh. Sophomores Hari Anbarasu and Pittayut Phonboon are the alternates.
Four teams remain in the fast-paced academic game show's 16-team single-elimination tourney: Sharon, Hamilton-Wenham, Arlington and Mystic Valley.
The 16 teams qualified for the tournament in October, out of 90 schools from Eastern and Central Mass. Sharon is playing for the first time.