The match was halted for about 10 minutes when a spectator collapsed during the final changeover.
The fans continued to fill the lower bowl during the final changeover, with Federer leading 5-0.
Suddenly Britain were in front, only for a mix-up in the final changeover to mess it all up for them.
KEY BISCAYNE, Fla .(AP) — Rising from her chair after the final changeover, Serena Williams glanced at her skirt and brushed away some lint, trying to look good in defeat.
By the end, Ferrero seemed to have taken root in the grass, while Hewitt ran to the final changeover leaping and punching the air.
It proved another calamitous competition for Britain's male sprinters, who were erased from the results for the fourth straight time in global championships after James Ellington failed to connect with CJ Ujah on the final changeover.
That was no small accomplishment given that Isner, 28, barely moved when Haas was serving late in the match and did not even sit during the final changeover, presumably because he decided that would have been worse for his exhausted legs.
Looking relaxed and on target from the start, he reeled off the first 11 points and won the first three games on his way to a 6-3, 6-2, 6-2 victhat that would have been routine if not for the fact that he and Hrbaty broke the mold by sitting side by side on the final changeover in the third set.
The United States crashed out after colliding with Britain, who dropped the baton, on the final changeover.
Christian Malcolm was part of the GB 4x100m relay team that was disqualified in their heat after a mistake on the final changeover between Daniel Talbot and Adam Gemili.
