Serena Williams overcame her injured older sister and the weight of history to retain her Wimbledon title.

For the first time in an all-Williams affair the eventual winner dropped the first set before emerging victorious, 4-6 6-4 6-2.

But Serena's win was bittersweet as sister Venus was clearly pained by stomach and thigh injuries which had threatened her participation right up to the scheduled 2pm start.

And Serena's muted reaction to her conversion of championship point after Venus had sprayed her final forehand long said it all.

Venus was hampered by her injuries as the hard-fought match progressed, and disappeared for a medical time-out after dropping her serve in the first game of the final set.

She returned having had strapping around her midriff readjusted but clearly remained discomforted and Serena charged home to her sixth consecutive win against her sister.

Venus' injury, which flared up again during her semi-final win over Kim Clijsters, had ensured world number one Serena started the match as a heavy favourite.

But it was Venus who got off to a flyer with Serena cranking up her unforced error count and seemingly troubled by the psychological issues involved with playing her hampered older sister.

And it was an equally uncomfortable day for the Williamses' mother and three other sisters who looked on anxiously from the players' box.

Venus, the 2000 and 2001 champion, broke in Serena's first service game and although she was broken back she gained a crucial second break in the 10th game of the set to win it.

Venus' form might not have been contributed to a classic but initially she made it competitive enough to have the majority of the Centre Court crowd engrossed.

Serena, who also beat her sister in last year's final, finally found her range at the start of the second set and raced into a 5-1 lead with Venus' dips of discomfort becoming more frequent.

Venus took one break back but Serena managed to serve out to level the match.

Venus' first serve visibly wilted as the third set progressed and she served a sad double-fault to give Serena the chance to serve out for her second title.

Afterwards Serena admitted to the crowd: "It was a little more difficult seeing as Venus was injured.

"It's really tough but it shows what a great champion Venus is and she is so inspiring for me."

Venus insisted she had not considered pulling out of the final despite her participation remaining in doubt until the 2pm scheduled start time.

"I came out because I just thought that the fans deserved a final and that's why I was out here.

"I want to thank my mum and my sisters and the trainers who really helped to keep me calm through it all."