On Sunday, Jannik Sinner and Carlos Alcaraz are expected to meet in the final of the U.S. Open, as they did few months ago at Wimbledon and the French Open. They have one of the most electrifying rivalries in sports, and their duels — fast, fierce and breathtaking — seem to push each other to new heights, as the two swap world No. 1 rankings.

“Alcaraz is prone to sometimes playing distracted matches, but every time he steps up to play Sinner, it’s the best tennis he’s ever played,” said Giri Nathan, the author of “Changeover: A Young Rivalry and a New Era of Men’s Tennis.”

“They see it as a privilege that they get to play each other — rather than an obstacle,” he added.

Rivalries can get a bad reputation, and some research has even linked them to more cutthroat and unethical behavior. But healthy rivalries can sharpen focus, boost motivation and improve your performance, even if you’re not competing on the world’s biggest stages.

“Rivalries encourage us to think outside of the box and to push our boundaries above and beyond what we know is possible,” said Matt Moore, a tennis coach and an associate professor of social work at the University of Kentucky.

Mr. Sinner and Mr. Alcaraz offer three key lessons about how to harness rivalry in your own life — whether you’re angling for a promotion, trying to beat your friend at pickleball or setting out to prove you’re the favorite child.

Lean into the curiosity.

The on-court rivals have different tennis DNA, with Mr. Sinner being calm and methodical, like permafrost, and Mr. Alcaraz running hot and unpredictable, Mr. Nathan said.