March curled home a sublime second half goal with his right foot to push Albion into a 2-1 lead but his nerves were jangling in the final moments when it appeared March had conceded a last gasp penalty.
The Albion winger collided with Trezeguet in the box and referee Michael Oliver awarded the spot kick. Oliver then surprisingly overruled his own decision following a VAR check on the pitch-side monitor.
The referee felt March's right leg connected with enough of the ball during the challenge, even though he caught Trezeguet with the follow through.
"For a moment I had my heart in my mouth but I got a bit of the ball," said March, who returned to the starting line-up after missing the Burnley match with an ankle injury.
"I haven't seen it back but sometimes with the follow-through you cannot avoid making contact."
Brighton opened the scoring in the first half thanks to a fine finish from Danny Welbeck but Aston Villa levelled soon after the break thanks to a close range effort from Konsa, after a Jack Grealish freekick.
But March's 56th minute right footed curler was his second goal of the season and sealed Brighton's second win of the campaign.
"My right foot is not the strongest. I just wanted to hit it well," said March whose other goal this season was a header during the 3-2 loss against Manchester United.
"It's a massive win. We've not been in the best of form but we have been playing well. We deserved the three weeks."
It was Brighton's first ever win at Villa Park in the Premier League and moves them to nine points from nine matches.
Their striker Welbeck was brilliant throughout and his dinked finish from Adam Lallana's through ball was just reward for the the 29-year-old former Man United man.
"It's a very important three points," said Welbeck after his second start for his new club. "We've had some good performances but today we got the result as well.
"I'm obviously happy to get off the mark with the goal. I just kept my cool and slotted it over the keeper."
On the decision to reverse the penalty at the end: "He got the ball didn't he? There is contact, it's a difficult one, but it's not a penalty."