With a new quarterback named Trent Dilfer, the Baltimore Ravens (7-4) have suddenly emerged as one of the NFL's quality teams on the eve of the easy section of their schedule, which continues against Dallas (4-6) Sunday and then Cleveland (3-8).

All season, the Ravens have been the league's model defensive power, blanking three opponents and playing 2-3 football through a five-game stretch in which they failed to score so much as one touchdown.

Then they changed quarterbacks and changed direction, bursting forth this month as an offensive-defensive power with the all-around strength to upset even the playoff-bound Tennessee Titans (8-2), 24-23.

The catalyst was, improbably, Dilfer, who, through a stormy seven-year NFL carrer, has inspired more abuse from more critics than perhaps any other contemporary quarterback.

* * * *

That's 2 for Troubled Trent

During the first two months of the season, Raven Coach Brian Billick, an offensive expert, apparently agreed that Dilfer's many querulous critics had a point.

In any case, he kept Tony Banks at quarterback in a punchless offense that continuously disheartened Baltimore's defense--the league's best--until, finally, successive defeats lowered the Ravens' won-lost record to 5-3.

At that juncture, Billick brought Dilfer in to beat Cincinnati, 27-7, as the Ravens scored their only touchdowns in six weeks.

But when, seven days later, a Tennessee cornerback intercepted Dilfer during a furious 17-17 fight in the fourth quarter--and returned the ball 87 yards for what seemed to be the winning touchdown--you could hear the anti-Dilfer fans shouting, from living rooms all over America, "Same old bum!"

They were wrong about that.

* * * *

Rams-Ravens-Raiders-Titans Tops

The Raven-Titan game matched teams with names that were unheard-of during all but 78 of the NFL's 81 years when, in large part, the old Chicago Bears and the old Green Bay Packers made pro football what it is.

The game also matched two of this year's four best pro clubs--placing St. Louis and Oakland in that company.

Indeed, if the Ravens are going to be respectable offensively now with their new one-two punch--Dilfer and rookie running back Jamal Lewis--they have defense enough to hold off any opponent.

Much the same can be said for the Titans and their one-two weapons, quarterback Steve McNair and running back Eddie George.

It was McNair who won the first Raven-Titan game in October, 14-6, before Dilfer's accurate passing tilted the rematch Baltimore's way, creating first- half leads of 14-0 and 17-7.

The Titans, on their home field, had fallen behind trying to run the ball.