Kevin Pietersen launched a robust defence of his right to mix left-handed strokes with his normal right-handed batting style after twice taking the unconventional route to hit New Zealand's Scott Styris for six.
England's centurion changed his stance twice as Styris was in his delivery stride, taking advantage of the shorter, less well-guarded boundary on the off-side by effectively making it the leg side and slog-sweeping the ball for six.
It raised questions over the fairness of his action for the fielding side but Pietersen dismissed criticisms as "ridiculous."
New Zealand captain Daniel Vettori believes bowlers should be able to counter by bowling wide of the crease on either side of the wicket, with immunity from leg-side balls being called wide automatically. But Pietersen rejected any notion that his latest innovative shot should be called into question.
"The reverse sweep has been part of the game for however long and I'm just fortunate in that I can hit it a bit further than most," he said. "I don't understand the criticism. It is ridiculous. Everybody wants new ideas, new inventions. It is a new shot and people should be applauding a new way to play, not criticising."
Vettori did not question the legality of the stroke, however. "They were very impressive shots," he said. "That's why people come and watch a guy like KP because he can produce that sort of performance.
"It is really good for the game that batsmen have the skill to do that. The only thing that I would say is that if you are going to bat left-handed you need to even it up for the bowler and let him bowl both sides of the wide line."
England skipper Paul Collingwood, his partner in a 136-run stand for the fourth wicket, confessed he had "closed my eyes" when he saw his team-mate adjust his position.
"I feel like I have been batting left-handed for the last month and I just thought 'oh, no' but he smashed it twice. He came down the wicket to me and said he had been thinking about it in bed last night."
Pietersen confirmedhe actively visualises playing the stroke if the opportunity to do so presents itself.
"The shot is something I practise, something I visualise," he said. "We were in a position where we needed to push the accelerator and it worked today. Some days it might not work but it did today. Then I thought I would give it a go again and it worked again."