What better way for the Canberra Cavalry, Australian Baseball League underdogs, to cap a magnificent resurgence than beat the back-to-back champions at a sold-out Narrabundah Ballpark.

Sean Tolar's flick to first baseman Aaron Sloan sealed the nailbiting 7-6 victory against the star-studded Perth Heat on Saturday night and sparked wild celebrations among the crowd of 2043.

The players were just as jubilant, dispelling the theory they merely treat their time Down Under as practice before heading back to the US for spring training.

One by one they were swamped by fans as they left the field. Pitcher Brian Grening, the backbone of Friday's series-opening 6-4 win, had high-fives and pats on the back coming from all directions.

As did lead-off hitter Cody Hightower, adopted as a favourite son among the Cavalry faithful over the past two seasons.

But the biggest greeting was undoubtedly reserved for catcher Jack Murphy, sporting one of the best mullets since the 1970s and a trademark moustache, leading to fans wearing T-shirts screenprinted with his image. Capitalising on that popularity is the next challenge facing the Cavalry, and the ABL. Many fans would readily admit they were jumping on the bandwagon, eager to be a part of history.

The Cavalry had transformed from strugglers in its past two seasons to collecting the minor premiership and earning home-ground advantage for the championship series. Those who had been there from the beginning understood how tough it was merely for the Cavalry to gain inclusion in the ABL's second-coming.

Petitions with thousands of signatures, generous donations and a groundswell of community support ensured Canberra would be part of the six-team competition.

Accusations of gaining an unfair advantage due to having extra American imports are ridiculous, given Canberra's smaller population compared to the other five teams.

Yet it was all the sweeter that two local products were the keys in bringing the Claxton Shield to the national capital.

Not in the squad at the start of the season, 19-year-old Sloan stood up when it counted to rightly be named the most valuable player of the championship series.

The youngest player in the ABL is set to return to work as a landscaper this week, but that may change after his outstanding hitting was broadcast to 40 countries on the Major League Baseball network.

Just as crucial was the go-ahead home run from veteran Michael Wells.

The 40-year-old, the only survivor from the days of the ill-fated Canberra Bushrangers, cleared the fence in the bottom of the seventh inning of game two to give the Cavalry a vital one-run lead that it never surrendered.

A $5 million improvement to the boutique venue over three years will enhance the enjoyment for fans.

The upgrade work, funded by the ACT government, will provide a new 1000-seat grandstand, which is estimated to be completed in 2016-17.

Next season can't come around quick enough.