Mercer wiped out the 14-point lead Burgin held early in the second half, but the Bulldogs scored the game's last eight points to win on the Titans' home floor for the second straight year.
They had beaten Menifee County the night before in what Irvine considered a significant win, but he acknowledged that beating Mercer was more meaningful -Â even in a game that had little meaning.
"I think we've been playing pretty well, and Mercer is a top three or four team in the region, but you get into these emotional games and you don't know what's going to happen," Irvine said.
Tim Riddle scored off an offensive rebound with 32 seconds remaining to pull Burgin within 56-55, and after a Mercer turnover, Patrick Cannada drew a foul and sank two free throws 10 seconds later to give the Bulldogs the lead.
Burgin's Logan Hill then blocked a shot by Mercer's Jake Mayes, and Zack Irvine, who led the Bulldogs with 15 points, hit four free throws in the final 8.5 seconds.
Between Zack Irvine's attempts, Mercer's Ward Dedman missed a contested 3-point attempt that would have tied the game.
Mercer (7-7) lost its second straight close game after five straight wins despite scoring five straight points to take a 56-53 lead with 54 seconds remaining.
The Titans forced 32 Burgin turnovers with their pressure defense, but that pressure may have helped as much as it hurt because it gave the Bulldogs numerous opportunities at the free-throw line, where they were 17-for-22.
"Our press got us back in the ballgame, but every time we fouled them, it allowed them not only to score but to also catch their breath," Mercer assistant coach Spencer Tatum said. "The hustle was there in the second half, but the fouling just negates the hustle."
Burgin shot 51 percent from the field, while Mercer shot 38 percent but had 21 turnovers of its own.
Jamel Taylor led the Titans with 18 points and nine rebounds, Clay Cinnamon added 13 points and Lyndon Compton had five steals.
Hill had 10 rebounds for Burgin, which hosts Mercer on Jan. 26. Trenton Claunch scored 12 points and Bill Beckerson added 11 points and six assists.
BURGIN (8-1) -Â Zack Irvine 15, Bill Beckerson 11, Tim Riddle 7, Patrick Cannada 7, Trenton Claunch 12, Logan Hill 8.
MERCER (7-7)Â -Â Jamel Taylor 18, Nick Patterson 2, Ward Dedman 7, Clay Cinnamon 13, Matthew McCloud 7, Matthew Honchel 4, Jordan Yeast 2, Jake Mayes 3.Burgin15284061Mercer7173556