Trailing all evening, the Patriots won it at the gun when sophomore standout Dylan Bartley swished a 3-point jumper from the corner as the clock expired.
Retiring Sullivan East coach John Dyer looked almost apologetic to Eastside coach Patrick Dameron when the two shook hands afterward, but the 32-year Patriot boss wasn't about to apologize for sneaking away with a win.
"We've had four of those (buzzer beaters) go against us," Dyer said. "Three or four of those, we had the last shot and didn't make it.
"So, we ain't giving anything back. I mean, they're hard-fought, everything's hard-fought ... but we hung in there. When we got it to (down) four in the fourth quarter, I felt like we had a real chance."
PATRIOTS CLAW BACK
East trailed 44-33 heading into the final period when Bartley and backup pivotman Austin Davis combined to give the Patriots a chance.
The Patriots (12-11) began with a pair of 3-point bombs from Bartley and another from Mason Montgomery, while Davis scored on three of four trips downfloor, making it a 55-51 game with 2:14 remaining.
And when Montgomery nailed his third 3 of the game, East suddenly was down just 55-54 with 1:40 to play.
Hard-working Eastside guard Grayson Whited skied high for a pretty 10-foot pull-up jumper in traffic, providing the Spartans (8-7) with their final lead at 57-56 with 19 seconds to play, setting the stage for Bartley's heroics.
The Patriots called two timeouts before drawing up a Bartley 3 from the corner.
A 6-2, 210-pound emerging star who made five 3s all told, Bartley settled behind a stone-wall pick and buried a shot he's launched thousands of times.
"I trusted my teammates and they set me up and I had a good look at it," said Bartley, who finished with 21 points. "It was just like in practice."
Bartley received solid support in the 11-point outings of Davis and Montgomery.
SPARTANS HAVE THEIR WAY
Dameron hated to lose, of course, but he generally liked what he saw.
"Bartley hit a good shot — he's a good player," the Eastside boss said. "Listen, we came over here and competed, and that's what I wanted. This game was put on our schedule strategically to make us better, and we got better tonight.
"I thought we handled their pressure well and had limited turnovers. We ran our offense, we got the shots we wanted. I thought our defense was pretty solid ...
"But this isn't about us," Dameron continued. "It's about them and that kid hitting a really good shot."
Eastside recieved 16 first-half points from bold Ethan Powers, who finished the game with 20, in claiming a 31-23 lead at intermission.
Whited scored 15 points to back Powers.
East, which got a timely steal in the final minute from Braden Standbridge, made 10 of 35 shots from beyond the arc.