LOWELL, Mass. -- Champions can win even when they've missed the scouting report.

"I didn't know she was a lefty," Serena Williams said after saving a set point in her 7-5, 6-1 victory against Iveta Benesova on Saturday in Fed Cup play. "I figured I was playing a right-hander."

For a moment, team captain Billie Jean King sitting next to her was speechless. Then, as that can never last ...

"I can't believe it!" King said, putting her hand on head in dismay. "That's great! Well, I'm going to get fired that's for sure! I'm out of here."

But since Serena won nine of the last 10 games after she figured it out and broke Benesova four times after being down 5-4, King's position seems secure. The United States is going into Sunday's matches with a 2-0 lead over the Czech Republic.

Earlier, Venus Williams demolished Daja Bedanova 6-0, 6-1 despite only getting 55 percent of her first serves in. King said the win delighted Venus.

"I've not seen her that excited in a long time," King said. "She was genuinely dancing up and down saying, 'That's the best I've played all year,' striking the ball."

Venus has only played in three other tournaments this year: the Australian Open (runner-up), Antwerp (winner) and the Nasdaq-100 Open (fourth round).

Venus said she's learned so much from coach Zina Garrison and King this week.

"I've been able to work hard and focus," Venus said. "I don't have any excuse of why I can't show up to practice -- like at home."

King said there was very little to work on with Serena's game.

"The one thing that all of us realized, you know, through practice this week is she's really the complete package," King said. "She doesn't really have a weakness. She has so many strengths. She's quick. She's smooth. Her technique is excellent on everything."

Serena's game also impressed Benesova, who when asked if that was the biggest serve she ever faced said "definitely." Then added, "well, I played against some guys. But it's almost the same, so …"

Serena said Benesova, ranked 71, threw her off at first but she adjusted.

"Well, I wasn't able to get in a groove," she said. "She was serving really well. She was hitting winners off all my shots and I had to think up a different strategy."

But once she did -- plus a healthy dose of anger at the thought of losing the first set -- Benesova never had a chance.

"I think I was going for too much (at first)," Serena said. "I think I should have just took some pace off the ball and just tried to move her around, do what I've been doing the past year and a half, as opposed to just blasting every ball."

That strategy has made her the No. 1 player while her sister has slipped to No. 3 despite finishing as the runner-up in the past four Grand Slam tournaments. Venus says her playing level is pretty good but she needs to work on the finer points.

"I think it's just the small things like getting more first serves in or more placement or a deeper second serve or more balls in play. I think Billie and Zina understand it's the small things that take you above and beyond the rest of your competition."

In the meantime, she's having so much fun at Fed Cup she's ready to come back next time. And showing an enthusiasm that has at times been lacking as little sis started taking the trophies away from her.

"I'm sold. I love it," Venus said. "I love playing for the team. It's an unbelievable feeling. Even though the scoreline was not as difficult today, I felt very, very excited. I was excited because it wasn't just for me -- it was for the team. We had a lead.

"It was great."

Cynthia Faulkner is the tennis editor for ESPN.com.