What a difference a year makes.

Entering NFL 2011 Week 6, there are 18 teams with a .500 or better record and half of them (nine) won six games or fewer a year ago. Those nine clubs, who have a combined 29-13 (.690) record this season, finished 2010 with a 49-95 (.340) mark.

Two of the teams making the biggest jump from a year ago meet this Sunday at Ford Field.

The 5-0 Detroit Lions (6-10 in 2010; 1-4 through Week 5, 2010) and the 4-1 San Francisco 49ers (6-10 in 2010; 0-5 through Week 5, 2010) have a combined record of 9-1 this season, compared to a 1-9 mark at this time in 2010.

The 49ers lead the NFC West and the Lions are tied with the Green Bay Packers for the top spot in the NFC North. All eight divisions have at least one new team either in first place or tied for the top spot. If that holds, it will be the most new division winners in a single season.

San Francisco improved to 4-1 last week with a 48-3 win over Tampa Bay. The 45-point margin of victory was the most by the 49ers since Super Bowl XXIV, when the club defeated Denver 55-10.

"The 49ers are a physical football team," says NFL Network analyst WARREN SAPP. "When you can run the ball and you can stop the run, that bodes well for you in this league."

San Francisco has had success at both and ranks fourth in the NFC in rushing (117.2 yards per game) and ties for third defending the run (76.4).

"Everybody is on the same page," says San Francisco running back FRANK GORE, who is one of four players in the NFC with 400+ rushing yards. "As long as we just keep working and take it one game at a time, and continue to get better every day on the practice field, I feel like we can do whatever we want to do."

The 49ers also lead the NFC with 14 takeaways and a +10 turnover differential. Quarterback ALEX SMITH, who ranks second in the NFC with a 104.1 passer rating, has thrown only one interception.

"It's all about football around here," says Smith. "The focus is on details. The focus is on football. The focus is on teaching. Players are executing and we're getting better every day. There's no secret. We just want to continue to take steps every single day and so far we've done that."

Detroit is 5-0 for the first time since 1956.

Hosting Monday Night Football for the first time in a decade, the Lions defeated Chicago in front of a loud home crowd. For the first time in team history, the Lions have won three games in a row in which they trailed at halftime. Comebacks aren't new for Detroit this year, as victories in Weeks 3 and 4 saw the team become the first club in NFL history to win consecutive games in which it trailed by at least 20 points in each contest.

"Detroit is a blue-collar town," says Lions head coach JIM SCHWARTZ. "Detroit has been through tough times before. Tough times don't last but tough people do. We feel a very strong bond to this city. Our work ethic reflects the city of Detroit's."

Lions wide receiver CALVIN JOHNSON leads the NFL with nine touchdowns and is the first player in NFL history with nine touchdown catches in a team's first five games. Quarterback MATTHEW STAFFORD ranks third in the league with 13 TD passes and his 19 touchdown passes over his last seven games are tied for the most by any Lion over a seven-game span (Pro Football Hall of Famer BOBBY LAYNE, 1951).

"We know we haven't played our best football game yet," says Stafford. "We've had some moments here and there. But we've got to keep working on executing and playing as well as we can. We know what's gotten us to this point and we need to keep that going to continue succeeding. We've got a big game on Sunday and we've got to try and do it again. That's the way this league is. There are 16 games and we've only played five. We've got to keep grinding and get back to work. We've got a tough team in San Francisco coming in."

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