The Paisley side earned a point in a goalless draw at home to Dundee United in their final SPL game ahead of the Hampden date against Hearts.
Lennon said: "It was an evenly contested game. We had a few attempts at goal so we've worked their goalkeeper, and they worked Craig Samson, who made a fantastic stop from short distance which was a key moment in the game.
"I'm absolutely delighted that we can go into a full working week of preparation for the cup final with no more games in between - it's been a demanding few weeks for us, but now we can focus on what the talk's been since the semi-final.
"We're just delighted to come of this game having picked up a valuable point; like every point we've gained this season we've had to fight and scrap and it was the same here.
"After the final, we then come into nine very important league games and that's our bread and butter, what we're primarily judged upon."
The St Mirren manager admitted that his players have been caught up in looking ahead to the final.
"I'd like to say it hasn't been a distraction but it has, there's no doubt about that, and the players are honest and will tell you that, but that's football," he said.
"Some will be playing in what they feel is the biggest game of their career, and we have a lot of young boys for whom hopefully it's the start and they have many big games within them.
"We'll leave no stone unturned - we want to go there on Sunday, bring the cup back and make it a memorable occasion for our fans."