There was more banter than birdies. And neither player needed to search for clues on the other’s body language.

It was obvious from the start of their Round-of-16 match in the 55th U.S. Senior Women’s Amateur on Tuesday afternoon at Wellesley Country Club that Caryn Wilson and Lynne Cowan were enjoying each other’s company.

They had faced each other once before, in the 1994 California State Amateur.

“Back when I was 12,” Cowan quipped.

“And I was 4,” shot back Wilson.

They arrived on the first tee with identical red golf bags emblazoned with “2015 California State Team,” and then they pulled out identical yellow golf balls.

“Are you using your California State ball marker?” Wilson asked.

“Are you using a No. 3 ball?” Cowan responded.

All that the scene was missing was Simon & Garfunkel’s “Old Friends” playing in the background.

“We were pretty loose at the start,” said Cowan, who is from Rocklin, a suburb of Sacramento. “I had to try and block out our friendship and pretend she was somebody I didn’t know. But it was weird.”

After Wilson’s 1-up victory, the two shared a warm embrace on the 18th green.

“I’m happy to win, but that wasn’t a fun way to do it,” said Wilson, who lives in the Southern California desert community of Rancho Mirage. “I just told her that I was sorry the matched ended like this.”

Wilson prevailed when Cowan chunked a 9-iron into the front bunker on the closing par 5, leading to a double bogey. It was one of the rare mistakes by either player in a match that was as tight as their friendship – after Wilson won the first hole, they halved 12 consecutive holes until Cowan won the 14th with a par.

Cowan’s other big mistake came on the 16th hole, after she had taken her only lead by winning No. 15. Trying to lay up short of a hazard crossing the fairway, she popped up her hybrid off the tee. The resulting bogey  squared the match.

“I was up and didn’t want to make a huge number, so I guess I played too conservatively,” said Cowan. “I should have just hit driver. That cost me the match.”

In the quarterfinals, Wilson will face another Californian, defending champion Karen Garcia, at 8:10 a.m. on Wednesday.

“I need to putt better,” said Wilson, who failed to convert a handful of birdie putts inside 10 feet. I struggled matching my speed and my reads this afternoon. I’ve got to figure that out.”

In some ways, Wilson and Cowan have forged an unlikely friendship. Cowan is a career amateur competing in her 30th USGA championship. In 2015, she was named one of the 10 greatest golfers in Northern California history, a list that includes U.S. Women’s Open champions Juli Inkster, Patty Sheehan and Paula Creamer, as well as two-time USGA champion Pat Hurst and longtime LPGA Tour veteran Natalie Gulbis.

Wilson regained her amateur status just three years ago after playing professional tennis and golf for years. She is one of only two people to have competed in the U.S. Women’s Open and the U.S. Open in tennis. The other is the legendary Althea Gibson.

A three-time tennis All-America who led the Cardinal to the 1982 NCAA championship, the first year the NCAA sanctioned women’s sports, Wilson turned to golf in 1989. She earned her LPGA Tour card 10 years later.

Wilson and Cowan became friends last year when they represented California in the USGA Women’s State Team Championship.

“We had a ball together on that team,” Wilson said. “We had one night when we talked about everything: politics, family, golf, our careers. It was fun. But I did not sleep a wink. She says we talked until 3 a.m., but I can assure you it was until I left for the airport in the morning.”

The shift in their dynamics – from being teammates and friends to becoming opponents – seemed to impact both players.

“I think we were both a little nervous. We both wanted to win, and we’re both very competitive, but it was fun,” Wilson said. “I think we’re both disappointed we didn’t make more putts.”

Afterward, the two friends teased each other and posed for a picture, with Cowan playfully contorting her face in anger. The match was over, but the banter wasn’t ending any time soon.

Rob Duca is a Massachusetts-based writer.