"I wanted to get my sports bet in, and when I realized they were having a Thursday night game, I got pretty excited," said Mele, who celebrated his 57th birthday by becoming the first person to place a sports bet at Dover Downs.
Delaware is now the only state east of the Rocky Mountains to offer legal sports wagering.
The casinos at Delaware Park near Wilmington and at Harrington Raceway and Casino in southern Delaware also began taking bets in advance of Thursday night's NFL regular season opener between the Pittsburgh Steelers and Tennessee Titans.
Under a federal appeals court ruling in a lawsuit brought by professional sports leagues and the NCAA, Delaware's sports betting is restricted to parlay, or multiple wagers on at least three NFL games. A bettor must pick all the games correctly to win.
Delaware officials were hoping to offer bets on single games and sports other than professional football, but the court said that went beyond what was allowed under the state's exemption to the 1992 federal ban on sports betting. Delaware was exempted from the ban because it had previously conducted an NFL sports lottery in 1976.
Brian Perry, 40, a warehouse logistics worker from Dover, was looking ahead to Sunday's games. He stands to win $27.50 on his $5 wager if his picks of the Eagles, Vikings and Packers are correct.
Perry chose not to bet on his favorite team, the 49ers, because they are going up against the Arizona Cardinals and he didn't like the odds.
"I'm all about the money," he confessed.
State lottery director Wayne Lemons, who was visiting the casinos Thursday, said there were no early reports of any glitches. Even though Delaware officials and casino operators are restricted to parlay, they are optimistic the betting will prove profitable.
"I'm feeling better and better," said Dover Downs Inc. president and CEO Ed Sutor. "I was just expecting parlays with three teams period."
Instead, the state lottery office, working with vendor Scientific Games, has come up with a variety of betting options, including "teaser" and "super teaser" parlay cards that offer bettors more favorable point spreads in return for lower payoffs. Gamblers also are allowed to forego the preprinted parlay cards and wager "off the board," picking games at the last minute based on the most up-to-date point spreads.
Minimum wagers start at $2, with a maximum allowable wager of $3,000. For each wager, bettors must pick the correct outcomes of at least three NFL games, or as many as 12.
Since bets placed Thursday also require wagers on weekend games, gamblers won't know whether they've won or lost until Sunday or Monday.