Jamey Chadwell thought his Charleston Southern football team was too uptight this week, so he did what smart coaches do: He arranged Thursday for an ice cream truck.

It drove right onto the practice field, silly clown music and all.

“We were making mistakes and the staff decided we needed to get back to being loose,” the first-year CSU head coach said.

“The ice cream truck came out and it was great. Some of our fat linemen ran as fast as I’ve ever seen them run.”

It worked.

Almost everything worked Saturday during a 31-26 victory over previously undefeated Coastal Carolina at Buccaneer Field. From a sack on the first snap of the game to a third-down end-around play for a critical first down late.

“We believed we could win,” CSU running back Christian Reyes said. “We just wanted to come out and be more physical. On paper, they’re a better team but we just wanted to come out and punch them in the mouth.”

The frequent roars of approval from a record crowd of 6,135 distracted traffic on University Boulevard as CSU fans answered success throughout the biggest game in Big South Conference history.

The best feel-good college football story in South Carolina is hard to ignore, and too full of contributions for a passing motorist to take in.

‘Amazing’ crowd

The Bucs improved to 10-1, two more wins than in the previous three seasons combined.

In the Big South’s first matchup of ranked teams, No. 16 upset No. 3.

The turnstile count at the stadium CSU players playfully call “The Dump” shattered the record of 4,523 set earlier this season against North Greenville.

“The crowd was amazing,” quarterback Danny Crogan said. “The great thing is, our stadium is so small but it doesn’t feel like that because it’s so loud. There were times out there on the field where I could barely get the signals to the offensive line, it was so loud. We’re so thankful for our fans for coming out. It’s huge for us.”

What defense; Coastal Carolina had scored 50 or more points six times this fall.

Crogan and Kyle Copeland, the two CSU quarterbacks with touchdown passes, were on the bench when this charmed season started and injuries challenged CSU depth.

Reyes, the 5-10 tailback who rushed for 117 yards and two touchdowns, opened the year as an unknown junior college transfer from Rouge River, Oregon.

It’s not over.

CSU — which has never played a postseason game — must take care of business against Gardner-Webb and Liberty to solidify the Big South’s automatic FCS playoff berth, or an at-large spot.

No doubt there is sweet/bitter new emotion in the Bucs-Chanticleers rivalry.

Rivalry heats up

There are 112.85 miles between the CSU campus in North Charleston and Coastal Carolina in Conway, and at this rate Georgetown will soon stand as the dividing line in a fierce football rivalry.

You’re either on one side of Sampit River or the other.

You liked CSU’s balanced attack, feisty hand-to-hand combat in the secondary and big push from both lines.

Or you’re as frustrated as Coastal Carolina quarterback Alex Ross after the Chanticleers’ season-low 26 points.

“We knew they were a good team,” Ross said. “We just didn’t come out ready to go.”

By the way, the Coastal Carolina head coach isn’t a billionaire, or so Joe Moglia insists. But as CEO of TD Ameritrade he did preside over a stock increase from $700 million to $10 billion at the on-line brokerage firm.

You don’t need Moglia’s degrees in Economics (Fordham) or Education (Delaware) to realize his 17-6 record at Coastal Carolina is good for the bottom line.

But how about Jamie Chadwell, off to a 10-1 start at CSU?

You don’t upset Coastal Carolina without a bunch of shrewd decisions, and he was smart enough to free up assets for ice cream.

Follow Gene Sapakoff on Twitter @sapakoff.