The former Stoke City and Millwall player was affected by a foot issue in the first few months of 2022, but produced a strong performance against the Gills, to put him and Wednesday in good heart for the visit of struggling AFC Wimbledon on Saturday.
Wednesday are now entering the home straight in their bid to secure play-off participation, with their home form - the best in the top four tiers in England - providing the bedrock to their quest to return to the Championship at the first time of asking.
The input of senior men such as Gregory, who has hit nine goals this term and been involved in 16 games, alongside others such as Barry Bannan, Sam Hutchinson, Harlee Dean and Massimo Luongo, is likely to be vital towards achieving that.
Moore said: "It was a massive moment (for Gregory).
"He is a leader and you can see the way he goes about it. He loves the game and wants to play and get out there. He did well and was the one who gave me the most headaches (with his fitness). But he just wants to play and credit to him. I am really pleased.
"It had been a long time since Crewe (Gregory's last goal), but what an emphatic strike it was (against Gillingham) and you could see he was in total control of it and he executed the finish really well into the bottom corner and that will settle him down. To get our number nine scoring again is really important at this stage of the season.
"Lee has had his injuries and we have had to work some minutes into him to get him back. We gave him 60 minutes, then 30 minutes and then another 60-odd minutes against Gillingham.
"He had a week to work and is in a position where he can complete games now and it was the same with Mendez (Laing)."
Wednesday are continuing to monitor Olamide Shodipo ahead of deciding whether to involve him in their plans against the lowly Dons, who this week appointed Mark Bowen to replace the outgoing Mark Robinson as manager.
On Shodipo, who returned to training this week, Moore said: "He is a player who can create something out of nothing and he will be 50-50 for Saturday."