Serena Williams matches Martina Navratilova with 306th Grand Slam Open-era singles win

Serena Williams didn’t need to offer words of self-assessment after 65 minutes of work, a straight-sets win over Vania King at the U.S. Open in the second round Thursday night.

Body language on the court said it all: a couple of annoyed looks and the shake of her head after her 6-3, 6-3 victory. Her mood brightened when she was reminded that she had logged her 306^th Grand Slam Open-era record singles win, tying the legendary Martina Navratilova.

The next topic bolstered her disposition as well. Williams, who came to New York with questions about her injured right shoulder, hit 13 aces against King, double-faulted twice and didn’t face a break point.

“It’s stable,” she said. “It’s stable. I just got to keep it like that. It’s two matches in, and usually you want to be able to play seven matches. It’s not even close to the halfway point.”

Williams dropped only one game to King the other time they played, two years ago in New York, also in the second round. This one looked as though it was going to follow the same path. Williams needed seven minutes to take a 3-0 lead, holding serve twice and essentially picking her spots.

The irritation likely came in the form of 28 unforced errors in a high-profile night session in front of famous friends. Beyonce and Jay Z were in Serena’s box and Williams had introduced Beyonce, who performed, at the MTV Video Music Awards on Sunday.

“Usually when people are there I try to play better, especially if they’re famous and they’re doing so great at their job,” Williams said. “It’s like I want to show them I’m good at my job too — minus today.

King noticed the star power, too.

“The crowd cheered at one moment and I looked up and it was Beyonce and Jay Z, and I’m like, ‘…I shouldn’t have looked up,’” said King, adding and joking, “…But it didn’t affect me actually. I’m like, ‘Oh, Beyonce’s watching me.’”

King talked about the impact Williams has had on the sport.

“My coach asks me before each tournament: ‘Who do you think is going to win the tournament?’” she said. “…I always say Serena. Who else can you say?

“You’re always surprised if she loses. No matter what shape she’s in, what condition. She’s always, for me, the best player in the world. I’m happy to be playing with the greatest female player, possibly greatest player of all time.

“I’ve never not picked her.”

Williams admitted that she is in a bit of a bubble in terms of her accomplishments and hearing recent accolades from the likes of Olympic stars, gymnast Simone Biles and swimmer Simone Manuel.

“It’s weird to have the Simones … Simone and Simone, I should say, to have them so influenced by me,” Williams said. “I’m still influenced by people. I’m still in this sport and I just never take that moment and look back to see all the things that I’ve done.

“I don’t want to become complacent.”

Following Williams-King, Olympic silver medalist, wild card Juan Martin del Potro of Argentina beat Steve Johnson, 7-6 (5), 6-3, 6-2, hitting 15 aces.

Inclement weather earlier in the day played havoc with the schedule on the outside courts and forced organizers to shift matches. Venus Williams played during the day and was pleased with her progress since the opening round, beating Julia Goerges of Germany, 6-2, 6-3, in the second round.

Venus, 36, first played in the U.S. Open in 1997 and reached the final, losing to Martina Hingis.

“People are probably intrigued that myself and a number of older players are playing quality tennis at this age,” she said. “It’s something that never happened before. Inquiring minds want to know.

“I guess 36 is the new 26.”

Lisa.dillman@latimes.com

Twitter: @reallisa