NEW YORK -- Venus Williams has spent much of this summer smiling because of the career resurgence she is enjoying, but her Olympic doubles partner says there's a more serious side of Venus that not everybody gets to see.

"On the court, the thing that stood out the most was just how fearless she was," said Rajeev Ram, who won a silver medal at the Rio Olympics while playing mixed doubles alongside Williams for the United States. "It didn't matter the situation, it didn't matter the moment, she believed that she was going to be able to deliver and I think that's a pretty unique quality."

Venus, now 36 and the No. 6 seed in women's singles at the US Open, may appear graceful on the court and happy off it, but there's an inner competitive fire that has fueled her success across an 18-year-career that has seen her win seven Grand Slam singles and 14 major doubles titles.

"Well, I told [Ram] when we got on the court, it looks like I'm really nice but I'm not," Williams said. "I think he learned that....I think he got to know that I don't take a loss for an answer."

Williams and Ram did lose the gold-medal match to fellow Americans Jack Sock and Bethanie Mattek-Sands, but the medal highlighted Williams' resurgence at an age when many tennis players are long retired from the tour.

By winning the silver, Williams became the first American woman to medal in all three events (singles, doubles and mixed); her five medals mean she now shares the record for most Olympic medals won in tennis.

This summer, she also reached the semifinals at Wimbledon -- her first Grand Slam semifinal since the 2010 US Open -- before losing to Angelique Kerber. Kerber would lose in the final to Venus' younger sister, Serena Williams, the world No. 1 who is shooting for a record 23rd Open-Era Grand Slam singles title at the Open.

As a result of her success this summer, Venus ascended to No. 6 in the rankings, her highest position since being diagnosed in 2011 with Sjögren's syndrome, an autoimmune disease of salivary and tear glands which can cause excessive fatigue among other things.

"As an athlete, you're always aiming for perfection, you want more and more and more," she said of the syndrome. "It's never enough. That's what I'm looking forward to, to peak every time I get on the court. That pretty much doesn't happen 'cause I'm always wanting to be better."

Here at the Open, she won her opening-round match on Tuesday over Kateryna Kozlova, 6-2, 5-7, 6-4. Next up is German Julia Goerges on Thursday, when Serena will also play her second-round match against fellow American Vania King in Arthur Ashe Stadium.

"We love playing on Ashe," Serena said. "Playing on the same day is always great. I feel like it's double the fun. It's always great to see Venus do well."

While Serena holds more major titles than Venus (22-7), Venus set a new record for most Grand Slam singles appearances with 72.

That's what a fearless approach to the game will get you. Through 18 years of ups and downs, triumphs and troubles, Venus Williams is still a factor at the US Open.

"I'm grateful and I'm blessed," Venus said. "All I'm hoping for is just health that I can keep that record going. I don't know when I'm going to stop playing. I don't have plans now. I'm playing too well to be thinking about stopping. I appear to be getting better each and every month."

 

VINCI TAKES OUT JERSEY'S McHALE

One year after upsetting Serena Williams in the semifinals and halting her bid for a calendar Grand Slam, can Roberta Vinci make another run?

The No. 7-seeded Italian had little trouble Wednesday in dispatching New Jersey native, Christina McHale, 6-1, 6-3, on Louis Armstrong Stadium to move into the third round.

Vinci hit 17 winners against 11 unforced errors and converted on 4-of-7 break points.

"She's a great opponent, she has great forehand, good serve," Vinci said of McHale. "But I think today I played better than the first round.

"It's incredible to come back here [after] last year with a lot of crowd. Last year was an amazing moment for me, for my tennis, for my team, for my family, for everything. This year is tough to repeat again, but step by step. I'm so happy that I won and [I'm in the] third round."

Vinci, who lost in last year's final to fellow Italian Flavia Pennetta, could meet No. 2 Angelique Kerber in the quarterfinals.

Follow Adam Zagoria on Twitter @AdamZagoria for updates throughout the U.S. Open.