Under Armour ripped up the final two years of an endorsement deal it had with golfer Jordan Spieth and signed him to a new 10-year deal, which it announced Wednesday.
Financial terms were not disclosed, but like most golf deals, the contract is known to include many performance-based incentives.
The company, which passed adidas as the second-best-selling sports apparel brand in America in 2014, signed Spieth in January 2013 shortly after he left the University of Texas to turn pro.
The deal guarantees that Spieth, 21, will wear only Under Armour head to toe, including golf shoes, which will hit retail later this year.
"I really enjoyed being on this journey with Under Armour since turning professional and I can't wait to accomplish great things together in this next phase of my career," Spieth said in a statement.
"He's athletic, he's young, he has the right character and he wins," Ryan Kuehl, senior director of golf for the company, told ESPN.com. "This is a testament to our investment in the golf performance space."
Kohl said Under Armour's strategy is to invest in fewer players, whose bodies are almost exclusively covered in Under Armour logos.
"We think that when other logos are on the player, it waters down our brand," Kuehl said.
When Spieth was front and center at the Masters last year -- he finished tied for second -- he had at least 10 Under Armour logos on him during all rounds.
Under Armour -- which has Hunter Mahan and Gary Woodland under contract -- is behind Nike in the golf shirt business, but its golf pants business has been robust in the last year. Kuehl says it's a realistic goal for Under Armour to take the top position in that category by the end of the year.
In Spieth's two-year PGA Tour career, he has finished in the top 10 on 18 occasions, including a win in the John Deere Classic in 2013.
In his last outing, in December, he won the Hero World Challenge at Isleworth by 10 strokes, shooting 26 under par.
Spieth is ranked ninth in the official World Golf Rankings.