The hosts managed to edge out Samoa in an entertaining encounter, with Huw Jones, Stuart Hogg, Peter Horne, Alex Dunbar and McInally (2) all crossing the white line for the hosts.
Finn Russell slotted over three conversions and two penalties while Horne also had one successful conversion, ensuring the Scots got off to a winning start in their autumn internationals.
Gregor Townsend's men take on world champions New Zealand at Murrayfield next Saturday and McInally, who was named man of the match, admits his side will have to produce a much better performance if they are going to defeat the All Blacks.
Speaking on BBC One, he said: "I'm delighted with the win, I benefited from the work the forwards did in front of me and I was at the back of the maul to touch them down. Forty-four points scored today but a lot of work to do ahead of next week.
"I'm just really pleased to be playing after not playing at all for them last year."