Eric Teesdale had a pair of RBI singles and Christian Walsh and Dan Baldino added RBI doubles for Sterling, which needs to win one of its two Colonial games this week - against Haddon Heights and Paulsboro - to clinch a berth in the Diamond Classic.
The Silver Knights also would clinch a berth if Haddonfield loses a Colonial game this week. The Diamond Classic field will be announced on Sunday.
"It would be a big deal if we were to make it," Sterling coach Chris Hoffman said. "We had a couple teams that won it [in 2002 and 2003] and we made it in '04 and '05 but we haven't made it since.
"We talk about having pride in the program and building the tradition and that would be something that could really add to it."
Chris Dengler had a two-run single and losing pitcher Mark Ostbye (five-plus innings, seven strikeouts) reached base three times for Haddonfield (8-6, 5-3), which had won five in a row.
"We didn't hit when we had opportunities," said Haddonfield coach Bob Bickel, whose team stranded 12 base-runners.
Mazzone delivered an RBI double in the fourth to tie the score at 4-4.
In the bottom of the sixth, junior Andrew Mottola worked a six-pitch walk to lead off for Sterling. Mazzone followed with the game-winning hit, a rope to left-center that chased Mottola all the way home from first.
"I've been slumping lately," Mazzone said. "I just wasn't making good contact. Coach [Hoffman] talked with me about keeping my weight back, staying on my back foot. I knew my team needed me."
Haddonfield 010 300 0 – 4 9 2
Sterling 300 104 x – 8 7 2
WP: Brett Mealey LP: Mark Ostbye
2B: S-Chris Mazzone, 2, Christian Walsh, Dan Baldino.
Watch a video interview with Sterling's Chris Mazzone at
Contact Phil Anastasia at 856-779-3223, firstname.lastname@example.org, or @PhilAnastasia on Twitter. Read his blog, "Jersey Side Sports," at www.philly.com/jerseysidesports