Neither the Scotland Under-21 international nor any of his team-mates had netted in the Scottish Premiership since beating Kilmarnock at the start of November.
But the frontman brought a 460-minute wait for a goal to an end when he struck away a first-half penalty against Dundee United before going on to complete his first top-flight hat-trick as Saints won 3-0.
However, May insisted his recent troubles in front of goal had not prayed on his mind.
He said: "It was only three or four tough games that we hadn't scored in - Aberdeen, Inverness, Hibs, when we were down to 10 men, and Celtic. I wasn't thinking about it too much. I'm always confident in my ability to score goals."
United boss Jackie McNamara made eight changes to his side after their 4-1 Boxing Day drubbing by St Mirren.
Only Radoslaw Cierzniak, Paul Paton and Andrew Robertson survived but with a patch-work side as opposition, Saints made the most of the opportunity and claimed their first home win over their Tayside rivals since November 2000.
May slotted away his spot-kick after 20 minutes as United defender Calum Butcher was penalised for clotheslining him in the box.
Terrors skipper Sean Dillon had undercooked a headed back pass and Butcher's last-man foul cost him a straight red, while May made no mistake as he rolled the spot-kick straight down the middle.
But May said: "I think we'd have won regardless of the red card. We started the better team. They made a lot of changes and I don't know what the thinking was behind that. We were confident before we saw their team and more so afterwards when we saw their big players weren't playing.
"We played well, we came out and made it a derby and battled away. The referee made the right decision.
"For me it was a penalty and the player was last man. I was on to the ball. It was a weak header back and I was getting there. He pulled me down. If I'm going down you know it's a penalty and he was last man."
He then blasted a brilliant second from a tight angle before wrapping up his treble with a tap in late on.