Their doubles title -- their third at the Australian Open and eighth Grand Slam title as a combination -- came at the expense of Daniela Hantuchova of Slovakia and Japan's Ai Sugiyama, who lost 6-3, 6-3 and had to dodge a number of stinging shots at the net, particularly from Venus.
"I just wouldn't want to face them too much. They are ferocious," Serena said of her sister's shots. The sisters have faced each other in seven Grand Slam singles finals.
"She's covering the whole net. At one point today, I literally stood back and she took care of everything."
It was a good tuneup for Serena's singles final Saturday, when she will face Russia's Dinara Safina.
With the temperature topping 113 degrees in the late afternoon, the roof on Rod Laver Arena was closed when the tournament's Extreme Heat Policy was again put in effect. It was opened later for the men's match.
Some top players avoid doubles, worrying that the extra time on court might hamper their singles prospects. While they took a long time off from doubles as both dealt with injuries -- resulting in them being seeded only 10th at Melbourne Park -- the Williams sisters have gotten back together recently, winning Wimbledon and the Olympic gold medal at Beijing last year.
"I have a great partner," Serena said. "I don't have to work too hard out there. Just hit some big serves. Venus hits some big serves. We put the ball away. Most of all, I love to play doubles. For me it's great practice, great fun. If I'm really fit, then I like to go for the win in both events."
Fun indeed. They dropped only one set in six matches, playing better as the tournament went along. They were chatting and laughing Friday as if they were playing with some friends.
"I think we complement each other on the court because we're both extremely positive," Venus said. "We never, ever in our lives have said nasty things to each other. We just don't operate that way."
There's also a different mood for them than in singles.
"I think that when you play good points in doubles, you tend to smile a little more, enjoy that point with someone else," Venus said. "It's definitely a different kind of feeling, 'cause in singles you're so focused, you don't even smile, you just move to that next point without any kind of elation."
The sisters held up their rackets to celebrate the win before hugging each other on court.
"I'd like to thank Serena for being the best partner," Venus said. "I wouldn't want to play with anyone else. She's amazing."
They have won doubles titles at all four Grand Slams, a milestone that Sugiyama had been hoping to achieve by winning here with Hantuchova.