Lennon had come off the bench at Newcastle for his debut in midweek before being handed a starting role against Premier League leaders Manchester City.
The 30-year-old was one of Burnley's star men as the Clarets claimed a fine point.
Dyche said of his new signing: "I'm really pleased. It was a tough to get on the ball in the first half, then we made the tactical switch to change wings and that was affective and he grew into the game more.
"He will grow, but not physically, as he is more used to what we are about. I think for him to get his first start in a big game like that is good," Dyche said of the former Everton winger.
"I think he is enjoying it and why would you not? It's a fantastic group of players who will give you everything. That's a great start point as a manager."
Defour took to Instagram to confirm the surgery had been successful, but he is set to be out for the remainder of the season and is likely to miss the World Cup this summer.