LONDON (Reuters) - Just hours after battling it out for the Wimbledon singles title on Saturday, the Williams sisters returned to Centre Court united as team mates to retain their doubles crown. Understandably looking a little tired, the duo took a while to get into full swing but as they powered to a 7-6 6-4 victory over Australia's Samantha Stosur and Rennae Stubbs they soon proved their rock-solid partnership was still intact. "There's nothing like winning a title with your sister," 27-year-old Serena told reporters. "It's really a good feeling." "Definitely," older sibling Venus chipped in with a smile. Serena, who had earlier downed Venus in straight sets to claim her third Wimbledon singles crown, hit a forehand long to gift the Australians a break in the third game of the first set. But as the number three seeds held serve to take a 3-1 lead Serena drew on her well-known steely determination, standing hand on hip as she gave her sister a pep talk before the start of the next game. The fourth seeded pair, who had dropped a total of just 21 games in their five previous doubles matches in the tournament, fought back hard, hitting every ball with powerful aggression to break 38-year-old Stubbs' serve and draw level at 4-4. "They're a really good team, so they definitely pushed us to play our best tennis on the most important points," said 29-year-old Venus. "Even if you're tired you ignore it, just keep the adrenaline going." The five-time singles champion netted a ball to throw away set point at 6-5. But the sisters dominated the tiebreak, with Venus securing a 7-4 win with a volley down the middle of the court. Their teamwork was solid in the second set, with Serena jumping in to rescue a shot Venus missed before volleying to clinch the pair, who already held eight grand slam doubles titles together, a break in the seventh game. Serving for the match the women's singles champion sealed her second title of the day with a powerful ace, jumping up in delight before embracing her sister Venus, whose beaming smile eclipsed her earlier disappointment. Having played a total of over three hours of tennis in Wimbledon finals on Saturday, the double act were too exhausted to contemplate celebrating their Independence Day victory. "We've had a long day," said Serena. "We're just still trying to figure out what we're going to do."