James Adducci won $1.2 million on his first sports bet when he wagered $85,000 on Tiger Woods to win the Masters this year.

Adducci is back with another huge bet, putting $100,000 on Woods to win the three remaining majors of the 2019 season and complete the Grand Slam, something no golfer has ever accomplished.

At 100-1 odds, Adducci would win $10 million if Woods could become the first.

Woods' next major start will come in the PGA Championship at Bethpage Black, where Woods won the US Open in 2002.

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When Tiger Woods won his fifth green jacket at the Masters in April, it's possible that no man was happier than James Adducci.

Adducci placed a whopping $85,000 bet on Woods to win the Masters at 14-1 odds, setting himself up for a payday of $1.2 million.

After the tournament, it was revealed that Adducci was not some wildly rich professional bettor, but rather a man from Wisconsin who just had a hunch that Woods was going to win. He scrounged up the money to fly down to Las Vegas and place his first sports bet ever.

Read more: The person who won $1.19 million by betting $85,000 on Tigers Woods to win the Masters had never bet on sports on before

Now Adducci is betting on Woods again.

According to Golf Digest, Adducci returned to Las Vegas to place a $100,000 bet on Woods to win the Grand Slam at 100-1 odds — a wager that could net him a cool $10 million.

Tiger Mania is back in full swing. Getty Images

No golfer has ever completed the current version of a Grand Slam in a calendar year. The closest a player ever came was when Woods won the US Open, British Open, and PGA Championship in 2000 and went on to win the Masters in 2001 — a feat that has since been dubbed the "Tiger Slam."

For Adducci to cash his bet, Woods will have to win three straight majors, starting with the PGA Championship at Bethpage Black. Woods is the favorite to win the tournament at 8-1, and after his big win at the Masters, it's likely he'll continue to be among the favorites throughout the majors this year.

Read more: Tiger Woods' massive, $20 million yacht has been docked in New York just days before the PGA Championship

Adducci told Golf Digest that his reasoning is based on how this year's major schedule plays to Woods' favor and his belief that Woods' comeback will only gain momentum as it continues.

"Tiger has history winning at Bethpage, and he won at Pebble, by the biggest margin in history," Adducci told Golf Digest. "This is a very unique situation. That's the way I'm thinking about it. We know that with every win, the energy level will get amped up. His game gets elevated. The expectation — does he play well under pressure? He's the definition of excelling under pressure. That's how my brain works."

A $100,000 bet might seem like a lot of money to risk on a historic occurrence coming to fruition, but after his previous bet paid off to the tune of $1.2 million, it's tough to fault Adducci for feeling bold.

The PGA Championship begins on May 16 at Bethpage Black.

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