Serena Williams, contemplating her fourth set point, took several deep breaths and composed herself just behind the Toronto baseline. She had already saved a break point with an ace down the middle -- her fourth of the game -- when a short ball from Nuria Parrizas-Diaz sent her scrambling toward the net. It never had a chance; Serena hammered an overhead winner and, despite the roar from the spectators, hers was a few decibels louder.

“Yahhhhhhh!”

She would go on to defeat the 31-year-old Spanish lucky loser 6-3, 6-4 on Monday at the National Bank Open. It was her first victory in more than 14 months.

As usual, Williams was coy discussing the subject of how much longer in her post-match press conference.

“I guess there’s just a light at the end of the tunnel,” she said, laughing. “I don’t know, I’m getting closer to the light, so .... Lately that's been it for me. I can’t wait to get to that light.”

What exactly does that light represent?

“Freedom,” she said. “I love playing though, so it’s like amazing. But, you know, I can’t do this forever. So it’s just like sometimes you just want to try your best to enjoy the moments and do the best that you can.”

UPDATE: On Tuesday, Williams penned an essay for Vogue discussing her decision to "evolve" away from tennis. Read the article here

No one inside the Williams’ camps is saying the summer swing on North American hard courts means the end of their competitive tennis, but this looks and feels like a well-deserved victory lap for Williams, part of the greatest sibling tandem in the sport’s history.

Eighteen-time Grand Slam singles champion Martina Navratilova draws parallels between retirement and suffering a loss.

“Nobody can tell you how you should mourn, just like nobody should tell you how to retire,” she said from her Miami home. “It’s totally personal. Maybe the girls made a pact, maybe not. Maybe they don’t know, they’re just playing it by ear.

“Every situation is completely different, obviously. There is no right way or wrong way to do it.

Serena, who turns 41 at the end of September, is a 23-time Grand Slam singles champion, an Open Era record -- ahead of Rafael Nadal (22), Novak Djokovic (21) and Roger Federer (20). Her last previous victory came last year at Roland Garros, last title at 2020 Auckland, New Zealand -- her 23rd -- and last major title was the 2017 Australian Open. She had lost the only two matches she’d played in the past 14 months and is ranked No.407.

“How did I stay there? I love the game,” Navratilova said. “That’s what brings people back, time and time again. Keeps you playing longer than you thought you would. Particularly, Venus and Serena. I remember them saying they weren’t going to play past 25 or something -- and here they are.”

Watch this: Serena's sizzling winner earns standing ovation

Venus, 42, is a seven-time Grand Slam champion, second among active players. The last of her 49 titles (Kaohsiung, Taiwan) came six years ago. Her last major title, her fifth at Wimbledon, was achieved 14 years ago. Ranked No.1,556, Venus, too, has lost a step or two.

Most recently, she dropped a first-round match in early August to Rebecca Marino at the Citi Open in Washington, D.C., in three sets. Venus’ last match before that was a year ago in Chicago, a straight-sets loss to Hsieh Su-Wei. Her record is 3-10 in the past 19 months.

Unlike the Williams sisters, Navratilova, did not keep her retirement plans a secret -- something she regrets.

“It was fall of ’93 and I said, `OK, next year is my last year,’ ” Navratilova said. “And I told the press that -- and I wish I hadn’t. It was a one-year-long goodbye.

“It just takes its toll, every week, every tournament is a goodbye. It got to be very emotional.

Pete Sampras, at the age of 31, won the 2002 US Open -- and never played another match. It wasn’t until many months later that he acknowledged his retirement.

“They’re trying to stay healthy, play enough matches,” tennis analyst Pam Shriver said. “I think they both realize -- with Serena losing to Harmony Tan [at this year’s Wimbledon] and Venus last week [in Washington, DC] -- matches, at this stage, are crucial.

“When you’re at that stage of the game -- not that I played into my 40s, but rather my mid-30s -- that it’s a tightrope with your body, right? You need to play enough, but if you play too much, you can be done.”

When Williams lost to Tan in the first round at Wimbledon, Navratilova knew she’d play again.

“That’s not how you want to go out,” she said. “As an athlete, you cannot accept that as the last match. I think it’s great that she can still come back. Look at Venus. She has played longer than we thought, longer than she thought -- but she just loves it. We’ll see how it plays out. I just hope they go out on their own terms.”

After her first-round win in Toronto, Serena did not exult. She clenched her fist, tipped her visor to the crowd and, only after shaking hands with Parrizas-Diaz, raised her arms slowly in triumph. It was a feeling she hadn’t felt in more than a year, a sensation that has sustained her for more than two decades of professional tennis.

Going forward, how many times she will feel that thrill again?

After a strong effort Monday, we at least know she will be back for her second match in Toronto.