By Simon Evans

Fri Nov 9, 2012 1:20pm EST

(Reuters) - If form through the first half of the National Football League (NFL) season is a guide, Sunday's clash between the Houston Texans and the Chicago Bears could be a potential Super Bowl preview.

The Texans lead the AFC with a 7-1 record and the Bears have an identical record, bettered in the NFC only by the unbeaten Atlanta Falcons (8-0).

Critics of the Bears point to their relatively easy schedule so far and the way they struggled against the toughest team they have had to face so far this season - the Green Bay Packers who beat them 23-10 in week two.

Certainly, the Bears face a much tougher second half to the season with the San Francisco 49ers, the Minnesota Vikings (twice), the Seattle Seahawks and the return with the Packers in their next six games.

"You don't win anything when you start 7-1 but it helps," said head coach Lovie Smith this week.

"We don't have a lot of injuries and I feel like our arrow is pointing up....we are pleased where we are," he added.

The Bears have the sixth-ranked overall defense in the NFL and that success has been complimented by the success of wide receiver Brandon Marshall.

The Bears traded for Marshall from the Miami Dolphins in the hope that he could re-kindle the relationship he enjoyed with quarterback Jay Cutler at Denver and the gamble has paid off.

Marshall is ranked fourth in the league among wide receivers having put up 797 yards and scored seven touchdowns, three of them in last week's 51-20 crushing of the Tennessee Titans.

"He's doing a great job for this offense. He's attracting a lot of attention and he's still able to play at a high level, catch balls and make things happen on a Sunday," said Cutler.

Cutler, though, will have to contend with Texans defensive end J.J. Watt, who leads the league in sacks (10.5) and also has 10 pass break-ups.

The Bears' offensive line has not always given Cutler the best protection possible and they will need to be well aware of the threat Watt poses, especially given his current level of confidence.

"I see opportunities for sacks against every offensive line. I've watched the film, you see opportunities, you get excited," said Watt.

Elsewhere, the Falcons look to defend their unbeaten record in New Orleans against a Saints team (3-5) that is showing signs of improvement after a 0-4 start.

Neither the Dallas Cowboys or the Philadelphia Eagles have lived up to expectations this season and defeat in their NFC East clash would leave the loser on 3-6 and facing an uphill battle to have any hope of making the post-season.

The New York Giants (6-3) look to bounce back from their loss to the Pittsburgh Steelers last week when they face another AFC North opponent the Cincinnati Bengals.

(Editing by Gene Cherry)