They came from all around the River City tonight to see Bo Jackson prove that Heisman Trophy winners can hit curveballs, maybe even to the moon.

Exactly 10 days after he opted to play baseball rather than football, Jackson officially began his professional baseball career with the Class AA Memphis Chicks of the Southern League. Jackson had a single in his first at-bat, two strikeouts and a groundout to the pitcher in tonight's 9-5 loss to the Columbus (Ga.) Astros at Chicks Stadium.

You half expected Jackson to do a Roy Hobbs job and send a pellet into the right field light tower, making sparks fly. The Chicks' largest crowd of the season, 7,026, and members of the Kansas City Royals front office, who smooth-moved other teams by selecting Jackson in the fourth round of the June 2 draft, watched him begin a career many thought he never would start.

The Chicks deployed Jackson as the designated hitter, batting him seventh, a most unassuming spot under the circumstances. But the crowd didn't miss Jackson, though, giving him a "Bo! Bo! Bo!" chant during a standing ovation. Jackson responded with a run-scoring single up the middle during a three-run first inning.

"I'm satisfied," Jackson said afterward. He said teammates offered him the ball he stroked for a single, but he declined, saying: "I've got enough baseballs at home in my trophy case."

Chicks players said tonight was even more electric than Sunday's game, when outfielder Ed Allen was married at home plate before the game, then celebrated by going zero for 3. Manager Tommy Jones said this was the team's biggest event "since they revealed the name of the Chicks' mascot last year."

Jackson, the 23-year-old former Auburn running back of power and grace, is the first senior Heisman winner since Army's Pete Dawkins in 1958 to not enter professional football immediately after his collegiate career.

Jackson also is likely the first athlete ever compared to both Walter Payton and Babe Ruth. In one breath, Art Stewart, the Royals scouting director, said today the club wanted to bring Jackson along slowly and methodically to keep pressure to a minimum, and perhaps would bring Jackson to Class AAA Omaha and then to Royals Stadium in September or maybe in 1987.

Then he uncorked a pressure-filled beaut, saying: "Bo's got Willie Wilson speed, the Clemente arm, the Mantle-Ruth power. I don't think there's anybody you can find going way back with his talent. . . . Our trainer tested the power of his arm, the biceps, you know. He was over-awed.

"He thought he was looking at the leg of a powerful athlete, not an arm."

Jackson turned down the bucks and Bucs of Tampa Bay in what reportedly was the largest contract ever offered to a National Football League rookie: a $7.6 million, five-year offer, which included a $1 million annuity. The Buccaneers had made Jackson the No. 1 pick in the NFL draft.

Instead, Jackson accepted a three-year deal from the Royals that his attorney, Richard Woods, today said included $200,000 in 1986 (half of which is a signing bonus) and salaries of $333,000 in 1987 and $383,00 in 1988. Woods said Jackson also would receive $150,000 if he is still playing baseball in 1988. Woods added that Jackson will receive what he believes to be the largest shoe contract ever offered to a baseball player.

You have to look deep to see the whole picture: Jackson's contract with the Royals includes several buyout clauses, which would enable Jackson to pay a substantial fee to the club and return to football. That might only happen if Jackson, who bats and throws right-handed, is unable to turn curveballs into missiles.

This afternoon, Jackson said, "I want to be treated as Bo Jackson, baseball player, and not Bo Jackson, Heisman Trophy winner, or Bo Jackson, the guy who turned down megabucks to play baseball." At least that's what he told some of the 150 or so reporters who watched him step out of his Alfa Romeo sports car and stand under a tent set up beyond the left field wall specifically for his news conference.

As Jackson fielded questions, teammates stood under a nearby tree and watched, wide-eyed. The caption under this picture should read: Big time hits the little time.

Chicks pitcher Jim Benedict said: "The first day Bo was here, we got hamburgers, and we'd never gotten any food before this. Maybe we'll get lobster next."

A security guard escorted Jackson everywhere -- from his car to the media tent, from the clubhouse to the field. Jones said Jackson would assume the role of regular right fielder Friday or Saturday.