Mount has gone 15 games without a goal and was dropped for the 2-0 defeat to Manchester United on Monday.
However, Lampard started the 21-year-old against Spurs.
Olivier Giroud, Barkley and Marcos Alonso were all brought back in and all three players were involved in the goal, which eventually proved decisive.
“It was a great goal for different reasons.
“Mason’s run (was important). Mason’s performance, I hope that gets digested properly afterwards.
“A lot of people talk about Mason and his goals but his work rate and his sharpness in his game today was unbelievable.
“Ross, I shouldn’t leave him out because he was similar today. He has the awareness to find Alonso and it’s as clean a strike as you can make,” Lampard told the media afterwards.