Richardson, a towering 23-year-old left-hander from Lincolnshire, refused to give ground in a three-hour duel, levelling the tie 1-1. His team-mate, Jamie Delgado, had lost in four sets to Black's younger brother, Wayne.
The best players in the house were sitting in the crowd - Tim Henman and Greg Rusedski, nursing injuries and supporting their Davis Cup deputies - and before the end of the afternoon they were roaring as loudly as the the most vociferous member of the long-suffering BATS (British Association of Tennis Supporters).
Richardson, 6ft 7in but dwarfed by his opponent in terms of experience and ranking - Black, at No 46, is 220 places higher - helped cut down on the difference in professional stature by producing 22 aces.
Even more impressive, however, was the heart Richardson showed in refusing to be cowed by his opponent's superior play in the opening set. And when it came to a test of nerve in the final set, the Briton again showed courage. First to break, for 4-2, he did not allow his confidence to be shaken when Black broke back and then drew level at 4-4.
It was Black, serving to stay in the match at 4-5, who was the one to crack, if only because of his opponent's relentless pursuit of the points. The Zimbabwean managed to save two match points, but had no response to Richardson's grand finale of two spectacular forehand drives down the line. At the conclusion, Richardson looked stunned, as if waiting for the umprie to confirm that he had actually won.
"I was told the Davis Cup was a unique experience, and it definitely was," an elated Richardson told reporters who had expected to be quoting Byron. Delgado, Britain's No 1 for the weekend, promised much before losing the opening rubber against Wayne Black, 2-6, 6-3, 6-1, 6-3. The 20-year- old from Warwickshire began smartly but then hit 13 double-faults, the majority on crucial points. "Nerves didn't come into it," he said. "I was just struggling with my serve.''
He began by showing the touch of a seasoned campaigner rather than an understudy about to start his first contest over the best of five sets. He broke in the opening game, after Black had double-faulted for 0-40, then swept into a 4-0 lead and had a break point for 5-0.
Although Black held serve on that occasion, and again in the seventh game, the general impression was that Delgado had the technique to wrong-foot his opponent as long he did not suffer a serious lapse.
The match began to fall apart for Delgado when he was serving at 3-4 in the second set. Having survived two double-faults, which put him down 0-40, he crafted a game point and had all the court in which to convert it after his opponent left the ball hanging high close to the net, begging to be volleyed away.
Delgado was unable to resist the a temptation to rise to the occasion and slam-dunk a smash, a la Pete Sampras. The leap was fine, but Delgado belted the ball into the net - slam-plonk. "A bit of sun came through one of the windows," Delgado said. "But I should still have made it.''
The mistake was costly. Black broke for 5-3, and served out the set on his third set point, driving a forehand that clipped a sideline.
"My momentum changed," Delgado said. He had two opportunities to break in the first game of the second set, but netted a service return on the first. He tamely netted a backhand to miss the second chance, although in this case an excuse might be made that he was startled at the manner of Black's mis-hit smash over baseline which had gifted him the opportunity.
Once Black had levelled the match, he swiftly lured Delgado into making further errors. Perhaps trying to overcompensate with his serve, Delgado double-faulted to lose the opening game of the third set and then failed to take any of three break points in the second game.
It was now Black's turn to rampage, and Delgado won only one of 12 games in a run which left him by two sets to one down and broken for 0-2 in the fourth. He fought back to 3-3, but a double-fault gave Black a fourth break point at 3-5, and he took it.