Graham has now scored six Blackburn goals since joining from the Stadium of Light.
And Lambert feels Graham's goals at the weekend were 'excellent' and 'different class.'
The Blackburn boss is particularly pleased with how much dedication the 30-year-old has shown considering he is only with Rovers on a temporary basis.
Lambert is quoted as saying by the Blackburn site: "Danny's goals were excellent. The first goal is different class, it was a great finish.
"The header as well was really good, so I'm delighted with him.
"Since he has come to this club he has been a massive help, a really huge help for us, and it is testament to him, in that despite being a loan player, he keeps producing."
It's interesting to consider whether the current Blackburn man would be of help to Sunderland right now - with the Black Cats so short on goals.
But Graham never seemed to cut it in front of goal at the Stadium of Light. Was he mismanaged or is he simply more suited to Championship football?
Blackburn travel to Rotherham for their next league game, while Sunderland travel to Stoke City in the Premier League this weekend.