Unbeaten in doubles since August 1999, the American sisters failed to live up to their pre-match boast that they were invincible.
"It was such a great match, who could believe it was a only first round doubles," Hingis said.
"Four players like that together on the court, all with grand slams, all in the top-10, it was so exciting."
Hingis and Seles, playing together for the first time, looked like cruising home when they won the opening set and raced 5-2 ahead in the third.
But the Williams sisters, whose 22-match unbeaten run included Wimbledon and the Sydney Olympics gold, fought back to win the next four games and serve for the match.
They held match point four times but failed to convert any of their chances before Hingis and Seles broke back to force a deciding tiebreaker which they won.
"We may have lost the battle but we can definitely win the war," said an undeterred Venus.
"They played real nice, they played consistently but we're confident we'll do a lot better."
Not to be outdone by her older sister, Serena picked up on Venus's theme at the post-match press conference.
"It gets annoying to play singles because we're always winning tournaments," she said.
"We end up with a lot of matches under our belt so we don't usually practise doubles."
Serena reached the second round of the singles but Venus will not play again until the Australian Open.
She insisted that she would not be under-prepared for the first grand slam of the year.
"If I"m not ready now then I should just go home," she said.