Dak Prescott is better right now than Tom Brady, Lamar Jackson AND Kyler Murray ... so says Drew Pearson -- who tells TMZ Sports the Cowboys star is a top-3 QB in the NFL.

The Dallas legend made the claim just one day after Dak carved up the Eagles on "Monday Night Football" ... saying he believes only 2 other QBs in the league are as good as Prescott is at the moment.

"Aaron Rodgers, Matthew Stafford, Dak Prescott," Pearson says. "Top three quarterbacks in the league, I would say, right now."

Dak has been tremendous through the Cowboys' first 3 games of the season ... completing 77.5 percent of his passes for 878 yards, 6 TDs and just 2 INTs.