The game looked like it would end goalless but Ashley Grimes popped up in the 86th minute to net the winner for the Imps, his sixth goal in seven starts on loan from Millwall.
Tilson said: "It wasn't a great spectacle because Port Vale made it difficult for us.
"That was probably the worst game I've seen for a long time. They set their stall out and played very defensively. But it was all about the three points.
"Once they changed formation the game opened up a bit and it probably suited us.
"The goal from Ashley Grimes was good enough to win any game. It was a fantastic finish."
Source: PA
Source: PA