Under Armour ripped up Jordan Spieth's old contract before he won his first major and gave him a 10-year deal, and it's already paid off big time

Jordan Spieth won his third major on Sunday with a thrilling back-nine at Royal Birkdale to win The Open, but he wasn't the only big winner.

In January 2013, Under Armour made then-19-year-old Spieth the face of the company's fledgling golf wing. Then, in January, 2015, Under Armour scrapped the final two years of that deal and gave Spieth a new 10-year contract.

That's right. Under Armour, which barely had a presence in the golf world five years ago, has arguably the face of the sport locked up through 2025.

While we don't know how much Under Armour is paying Spieth - golf deals are often heavily incentive-based - it was a huge commitment for a young golfer who had yet to win a major. It also sounds like UA went all in on the 21-year-old.

Here is how Golf Digest described the deal at the time:

"The deal, which industry insiders say has 'Tiger-like numbers,' includes an eight-figure guarantee annually, bonus benchmarks (for things like winning a major), stock options and, in the future, a signature line of clothing."

In terms of length alone, the 10-year deal matched the deal Rory McIlroy received to replace Tiger Woods as Nike's top golfer.

And Under Armour reportedly wanted to make it even longer.

When Spieth and Under Armour negotiated their first deal, the company initially talked about a 25-year contract, according to Darren Rovell of ESPN.

Of course Spieth was not an unknown commodity, having won the US Junior Amateur twice, and Under Armour still had to persuade the youngster to wear its logo head to toe. According to Rovell, UA had three things going for it.

1. The company promised to feature Spieth as an athlete and not just as a golfer: This appealed to Spieth "because he saw himself as athlete. He's good in almost every sport he tries."
2. Under Armour does not make golf equipment: This "turned out to be a huge advantage for Under Armour, as Spieth didn't have to change equipment to make a deal."
3. Hunter Mahan: "Of the four golfers (at the time) that UA had under contract, the one who had the biggest deal, Hunter Mahan, was represented by Jay Danzi, who also represented Spieth."

While Spieth often seems understated in celebrating his major championships, Kevin Plank, the CEO and founder of Under Armour, has not been.

"Thanks to Jordan, our company grew up today," Plank told ESPN after Spieth won his first major in 2015. "He was like apple pie with a golf club. There was nothing more Americana than Jordan Spieth this weekend."

That last comment may have been an indirect shot at Nike and other golf-apparel giants, which have made points in recent years of dressing their top athletes, including McIlroy, in very bright colors.

So while some golf fans still clamor to get Tiger back, it looks now like Spieth is indeed the real deal and here to stay on top of the golf world. And the upstart apparel company that wants to take down Nike in golf and beyond appears to be winning the golf apparel war for now thanks to a huge gamble two years ago.