Resorts Casino Hotel and DraftKings Inc. on Monday became the first companies to offer online and mobile sports betting legally in New Jersey.

A week after receiving state regulatory approval, the companies launched DraftKings Sportsbook - an app and website offering sports fans the ability to place multiple and live in-game bets on major U.S. and international sports.

"We have put immense thought and significant resources behind the development of DraftKings Sportsbook and I'm confident that sports fans in New Jersey will enjoy using it to make the experience of watching the games even more interesting and thrilling," Jason Robins, CEO and co-founder of DraftKings, said in a statement on Monday.

Officials with Resorts Casino Hotel could not immediately be reached to comment on Monday.

The companies won a heated race to be the first to offer mobile and online sports betting in New Jersey.

State regulators are considering applications from several other companies and could soon approve additional online providers. Four casinos and two horse tracks currently offer in-person sports betting.

DraftKings is a global sports technology and entertainment company headquartered in Boston and offering daily fantasy sports contests across 11 professional sports in eight countries.

The company was founded in 2012 by Robbins, Matt Kalish and Paul Liberman.

Gov. Phil Murphy signed a law earlier this year legalizing bets on sports games, both online and at the state's casinos and racetracks.

The move capped the state's nearly decade-long battle to tap into a market that has largely existed only in Las Vegas and through illegal bookies.

In May, the U.S. Supreme Court threw out a federal ban on sports gambling that had been in place for more than 25 years.

The ruling has allowed any state to legalize sports gambling. New Jersey is the second state to do so.

Other states -- including New York and Pennsylvania -- are currently mulling sports-betting laws.

Anthony G. Attrino may be reached at tattrino@njadvancemedia.com. Follow him on Twitter @TonyAttrino. Find NJ.com on Facebook.