Needing only a point to virtually guarantee qualification to the second round, a lethargic Russian side failed and they were beaten 3-2.
In the last 10 minutes there were signs that Russia were capable of achieving the result they needed, but by then they were 3-1 down.
Dmitri Sychev's late strike offered a glimmer of hope, but the equalising goal proved beyond Russia.
Pavlov said: "The game was very tense but it is a pity that the way we played the game today was an indication of our level.
"We could have scored another goal but frankly they were the better team.
"We did not have much luck in the match. A number of our players played at their best but generally we did not perform well enough.
"Towards the end we were trying to keep the score as it was (1-1) and that harmed us.
"I want to congratulate Belgium on their victory, though, and wish them good success in their future games in the tournament."
Belgium finish second in the group and next take on group C winners and new tournament favourites, Brazil.