With Tony Romo again playing like a Pro Bowler, the Dallas Cowboys have established one of the top offenses in the league.

Rex Grossman and the Chicago Bears offense are stumbling, but the team’s vaunted defense looks as stingy as ever.

The Cowboys look to continue their impressive start when they visit Chicago on Sunday night in an early matchup of two of the NFC’s top teams.

After defeating the New York Giants 45-35 in its season opener, Dallas beat Miami 37-20 last Sunday. The Cowboys (2-0) lead the league with 82 points, their highest total after two games since 1971 (91).

Neither of Dallas’ first two wins came against teams which had winning records last season, leaving this contest as easily its biggest test to date.

The defending NFC champion Bears (1-1) have allowed the fourth-fewest points in the league (24) and the fifth-fewest yards (544).

They defeated Kansas City 20-10 in their home opener last Sunday for their 13th win in 15 regular-season games at Soldier Field, holding 12 of those opponents to 10 or fewer points.

Chicago’s rush defense has proven to be especially tough, shutting down the league’s top two rushers from last season. The Bears held the Chiefs’ Larry Johnson to 55 yards on 16 attempts after limiting reigning league MVP LaDainian Tomlinson to 25 yards on 17 carries in their season-opening 14-3 loss at San Diego.