If the 16 teams in the Joe Hartmann Diamond Classic had been seeded before the start of the tournament, Buena likely would have been 13th.

Or 14th.

But in the end, the Chiefs stood alone as champions.

"I never expected this," said junior outfielder Justin Geri, who played a pivotal role in two dramatic victories on Sunday. "It's just unbelievable."

Buena completed a remarkable weekend with a remarkable victory, beating St. Augustine, 9-8, in a Diamond Classic title game that ended when the Chiefs executed a textbook relay to throw out the potential tying run at the plate.

"Perfection," Buena coach George West said of the relay from rightfielder Geri to shortstop Anthony Lopez to catcher Manny Colon.

The bang-bang play ended a weekend in which Buena knocked off Holy Spirit on Saturday, then beat Gloucester Catholic and St. Augustine on Sunday.

Those three teams entered play with a combined 63-5 record, and Gloucester Catholic and St. Augustine are No. 1 and No. 2, respectively, in The Inquirer Top 10.

"We looked at it as David vs. Goliath," West said. "It's amazing what a little Group 2 school was able to do. It's unexplainable."

The loss ended an exhausting day for St. Augustine's seniors, who graduated in the morning, then helped the Hermits to a 10-inning, 13-12 victory over Eastern in Sunday's semifinals.

Buena's semifinal victory was even more notable, as the Chiefs upset a Gloucester Catholic team that had been rolling over South Jersey competition. The Rams had beaten Buena 13-2 on May 3.

"I never expected that," said Geri, who delivered the key hit, a two-run single, in Buena's three-run rally in the sixth inning against Gloucester Catholic.

In the final, Buena centerfielder Rob Bunton led the way with three hits and four RBIs.

The Chiefs built a 9-4 lead but the Hermits battled back as Misael Aponte had an RBI single in the fifth, Anthony Cocuzza rapped an RBI single in the sixth and Carlo Randazzo delivered a two-run double in the sixth.

In the seventh, the Hermits put runners on first and second on Cory Dick's double and Christian Adorno's walk. With two outs, Ed Charlton ripped a liner into right-center that looked like a game-tying, two-run double.

But Geri raced into the gap and bare-handed the ball. He fired a relay to Lopez, who whirled and fired a strike to Colon for the final out.

"Give Buena credit," St. Augustine coach Mike Bylone said. "There's no question they deserve it."

St. Augustine 020 113 1 - 8 14 1

Buena 001 530 x - 9 7 2

WP: Chris Capriotti. LP: Kevin Baxter.

2B: SA-Carlo Randazzo, Cory Dick, Ed Charlton.

SEMIFINALS

Gloucester Cath. 000 120 0 - 3 9 1

Buena 100 003 x - 4 6 0

WP: Jarred Corniell. LP: Bill Mendek

2B: GC-Brooks, Alessandrine, 2.

Eastern 003 010 700 1 - 12 10 2

St. Aug. 143 000 300 2 - 13 12 1

WP: Cory Dick. LP: James Santore.

2B: E-Matt Lawson, Sean Hunter, McCoy Bean, Mike Marchitto, Tyler Love; SA-Barry Buchowski.

HR: SA-Carlo Randazzo, Ed Charlton, 2.

Contact staff writer Phil Anastasia at 856-779-3223 or panastasia@phillynews.com or at PhilAnastasia on Twitter.