When Kirk Spahn and Jennifer Alden exchanged marriage vows under towering California redwood trees, Ms. Alden, a former actress who played a bride in the film “Wedding Crashers,” acknowledged the many obstacles she overcame on this journey to the altar.

For starters, there was that troublesome brain tumor.

“You know the joke ‘It ain’t brain surgery?’” said Ms. Alden, 37, a California native who spent summers at Alden Vineyards, her family’s Sonoma County ranch, where she mastered off-road motorbikes and horses. “This time, it was.”

Greg Alden, an older brother, said, “Jenny grew up more rough and tumble than one might expect from her Hollywood good looks.”

The tumor was discovered in 2012 after she was flipped out of a hammock. The growth near Ms. Alden’s left ear was unrelated to that mishap, and was considered serious.

Drawing on her acting career, she started a blog, Adventures in Brain Surgery, and posted short videos online about her diagnosis and options. She included her thoughts on what might happen if she lost the ability to speak, which was a real possibility. Even as chunks of her honey-blond hair were shorn for her eight-hour operation, her kooky expressions and wide smile prevailed.

At the time, Ms. Alden was a newlywed, having married a longtime beau the previous year. But while recovering from her surgery in September 2012 (the tumor proved to be benign), she found herself alone.

By May 2013, her marriage ended, and her sunny demeanor, too, looked to be in danger. “But Jenny is able to roll with the punches,” said Mr. Alden, who is the chief executive of Woodside Hotels, the family’s business.

So after a rough divorce, Ms. Alden recovered and started dating.

She was scrolling around Facebook in early 2015 when a dark, good-looking man popped up in a list of “people you may know.” She didn’t think she knew Kirk Spahn, but she wondered if she might want to.

From his profile, she discovered that Mr. Spahn had attended Dartmouth, where Ms. Alden graduated. He had just moved to Los Angeles, so she messaged him: Did they know each other in college?

Mr. Spahn, now 39, an accomplished tennis player who had competed for Dartmouth, had no problem recalling her — having harbored a mad crush. He had saved a photograph of her jumping into an icy New Hampshire pond in a leopard-print bikini.

She had a college boyfriend and didn’t have any idea that Mr. Spahn existed.

“You look familiar,” he messaged coolly, feeling anything but. They exchanged flirty texts over the next week, which led to a dinner date.

Yet when Ms. Alden opened her front door, the gracious, easygoing Mr. Spahn, who counts internationally known businesspeople and world-class athletes among his intimate friends, froze entirely, his nerves a jumble.

Ms. Alden, now working in client relations and digital strategy for Palo Alto Investors, a hedge fund focused on health care, was as beautiful — and effervescent — as he remembered.

Over dinner, his freeze thawed — only too much so. Mr. Spahn gushed nonstop on life since college. He was a founder of a spirits company, TY KU Sake, along with the Institute for Civic Leadership, an educational nonprofit for youth, before starting ICL Academy in 2014, a high school focused on social impact and civic leadership for children in the performing arts.

In fact, education was his family’s business. His father, Stephen Spahn, is the chancellor of the Dwight School, a high school in New York City that also has international campuses.

Ms. Alden, who could barely edge in a word, found Mr. Spahn’s over-the-top enthusiasm about education and sports somewhat charming, but her divorce and a few years on the dating scene made her alert to red flags. Always direct, she asked if Mr. Spahn perhaps had attention deficit hyperactivity disorder.

He didn’t, he simply buckled under pressure. At evening’s end, when Ms. Alden gave him a perfunctory pat on the back, he was well aware he had blown it.

Nevertheless, Mr. Spahn’s competitive spirit was reignited along with his collegiate ardor. If Ms. Alden had seemed perfect for him at Dartmouth, she was more so now: sweet, smart and, in a city brimming with smoke and mirrors, without pretense. She was a city mouse who adored nature, an avid skier, and clearly — the A.D.H.D. comment — someone who did not lack candor.

In matters of romance, they also had commonality. In 2013, he had ended a relationship with his fiancée shortly before the wedding they’d planned to have in the Caribbean. The breakup had been excruciating, but Mr. Spahn, who longed to start a family, felt that the marriage wouldn’t have lasted.

After the disastrous date with Ms. Alden, he was down but determined to fight his way back. A few days later, he showed up at a party she casually invited him to. To underscore her lack of romantic interest, Ms. Alden pointed out to Mr. Spahn the many single women in attendance.

But as Ms. Alden set off toward another man who beckoned to her, Mr. Spahn blocked her path. Channeling the “do the opposite” rule made famous by George Costanza from “Seinfeld,” he decided to do the thing he would never do.

“You put me in the ‘friend zone,’ and I don’t want to be in the ‘friend zone,’” he told her. Then, with one hand on the nape of her neck, he kissed her. She, too, made a move out of character: She kissed him back.

“His confidence excited me, and the kiss was perfect,” said Ms. Alden, who recalled that the chemistry that was missing in their first encounter had “entirely combusted.”

They talked until morning, but this time conversation was an easy volley, with Ms. Alden becoming captivated by Mr. Spahn’s warm grin, kind manner, intelligence and passion, and quirky sense of humor. The next day, he boarded a plane, but he cut that trip short to return to Ms. Alden’s side.

“We’re both silly but hard-working, and we love life passionately,” Mr. Spahn said.

Shiv Vasisht, a New Yorker and Mr. Spahn’s best friend since high school, said, “Like Kirk, Jenny has had a lot of opportunities in life but is amazingly grounded and generous.”

“Kirk is all action and loyalty,” said Brandon Short, a former linebacker for the New York Giants, who cited Mr. Spahn as a pivotal player in his life. (After Mr. Short left professional football, Mr. Spahn coached him to go to business school, even helping with his application.)

Within weeks, Mr. Spahn lobbed a marriage proposal. Yet it wasn’t until late August at a practice session for the United States Open that a pink diamond ring appeared. In a well-choreographed prank, Mr. Spahn popped the question, with the help of the tennis luminaries Novak Djokovic and Tommy Haas, to a very surprised Ms. Alden, who was sitting in the referee’s perch in Arthur Ashe Stadium.

“I know a lot of very inspiring people, but I’ve never met anyone as inspiring as Jenny,” Mr. Spahn said. “She makes the bar I’ve set for myself even higher.”

On May 7, the couple were married at Nestldown, a private estate in the Santa Cruz Mountains with acres of blooming gardens, California redwoods and koi-filled ponds. Two hundred guests, some who had flown in from as far as New Zealand, London, Madrid and Dubai, huddled under blankets beneath a threatening sky on the unseasonably chilly afternoon.

The groom entered to the accompaniment of “Eye of the Tiger”; “It’s a classic, the one athletes listen to get pumped up,” he said. Following him were a string of nine groomsmen including Mr. Short; Mr. Haas; Nirav Tolia, chief executive of Nextdoor.com; and a Saudi prince, whom the groom knows through his leadership work.

The bride, in a sequined Ines Di Santo gown, walked delicately down a steep, slippery path to a lakeside clearing in the well-tended forest where Dr. Joon Yun, a radiologist who became a Universal Life minister for the event, for whom Ms. Alden works at Palo Alto Investors, waited to officiate. Dr. Yun thanked the couple for letting the guests “crash your wedding.”

In his vows, the groom said, “From the first glimpse of your smile, you were always with me even though you didn’t know it,” which evoked knowing laughter from the crowd. He thanked Facebook for the algorithm that brought them together. He said, “Together we will leave the world a better place.”

The bride, in turn, called Mr. Spahn her “twin flame,” and with characteristic optimism, said the obstacles that had kept them apart through the years were simply “steppingstones” to being together.

The former tennis star Monica Seles, a friend of the groom, recited a blessing, urging the couple to offer each other “shelter from the rain.”

Sure enough, skies stayed bright through the evening, and despite the mud staining the hem of her dress, so did Ms. Alden’s smile.