The Chicago Bears travelled to Detroit undefeated at 3-0 and leading the NFC North Division but it was the Lions who looked like the more complete team at the end with a 40-32 victory. The Lions scored 27 points in the second quarter to turn a 10-6 deficit into a 30-10 halftime lead.

The Bears were beaten in all three phases of the game and their two touchdowns in fourth quarter garbage time only made the game look closer than it was.

Reggie Bush kept the Lions attack rolling by putting together the third best rushing game of his career. He carried 18 times for 139 Yards, a 7.7 YPC average and 1 Touchdown. Matthew Stafford recovered from a rough start to complete 25 passes in 35 Attempts for 242 Yards, 1 Touchdown, 1 Interception and a 88.0 Passer Rating.

With the Lions now on top of the NFC North Division with a 3-1 record here are the five things we learned.

The Bears defensive line has failed to impose their will on anyone in the first four weeks.Stafford Dropping Back

The Lions kept the Bears' defensive line in full retreat nearly all game and opened holes at will for Reggie Bush to exploit. They have also failed to generate an effective pass rush through four games this season.

It didn't help the line that there was no help from the linebackers or safeties once Bush broke past the line of scrimmage. Chris Conte in particular played a terrible game. He looked tentative and ended up on the ground wrapping up air more than once when faced with Bush slashing through the line.

Julius Peppers emerged to force a fumble and registered one sack of Stafford, the only time the Bears dropped Stafford all afternoon. That gives the defensive line 3 Sacks in four games. Even with the blitz help they brought against the Steelers they only have six for the season, one of the worst totals in the league.

The Bears 2013 defense has lost the ability to control games.

The Bears were the third toughest defense to score on in the NFL in 2012 behind the Seattle Seahawks and only four points behind San Francisco 49ers. This year they were at No. 20 going into the game against the Lions and that ranking is going to be a lot worse after Week 4 is over.

The Bears have carried forward their ability to create turnovers and have returned two interceptions and one fumble for touchdowns this season but that's the only 2012 trend they've been able to maintain.

The only thing the Bears have been able to count on the past 4+ seasons is that, even if "Bad Jay" showed up for a game, they were never completely out of it. At the end of the first half, after two Cutler interceptions, the Lions were ahead 30-10 and the game was too far out of hand to catch up with.

Today was the day for bad Jay.

Let's face it, Bears' fans knew a day like this was coming. After the offense put the Bears in front 10-6 the mistakes started coming. As the rush pressure from the Lions' defensive line increased Cutler began hearing steps and his play regressed to pre-Trestman levels.

The first interception across the middle was created by an excellent play by Lions safety Louis Delmas who slipped in front of Alson Jeffery as the ball arrived.

The second and third interceptions were all on Cutler. The second was a back-foot throw towards Brandon Marshall that sailed into the arms of Glover Quinn and the third was on overthrow to Jeffery that he couldn't have reached with another two feet of height under him.

The capper to the game was late in the third quarter when Ndamukong Suh pushed through Kyle Long to force a Cutler fumble while Nick Fairley picked up the fumble and rumbled 4 yards to the end zone for the touchdown.

Even with everything that went wrong in this for Cutler it's important to note that he kept his head in the game and continued playing hard to the very end. The team had no business being within one score from tying the game before falling short. That is how the Bears won their first three games and how they'll continue to win this season.

Suh and Fairley are a devastating duo in the middle of Detroit's defensive line.Fairley Touchdown

Suh has been a beast to deal with in the middle of the Lions' defensive line but Fairley hasn't been able to stay healthy and on the field so far in his career. If the first four games of the season are any indication the Lions will be formidable up the middle this season.

To emphasize the importance of that combo in the middle of the line, the only game Fairley missed this season was the Lions' 24-20 loss to the Arizona Cardinals.

This big pre-game big match-up centered around Suh against Bears rookie right guard Kyle Long. Suh picked up his first two sacks of the season and caused the fumble that led to Fairley's touchdown, Long handled himself well but still received his first taste of adversity after the string of successes he's achieved to start his NFL career. Together, this is only the first act of many the two will have in their NFL careers.

Matt Forte is returning to form as an all-around weapon on offense for the Bears.

In 2011, Forte was leading the NFL in Yards from Scrimmage before injuring his knee against the Oakland Raiders and missing the remainder of the season. Last year he struggled in an offense that had no idea how to play to his strengths.

He was ninth in the league in All-Purpose Yards through the first three games of this season with 363 and added 95 yards rushing and 22 yards receiving against the Lions. He hasn't broken 100 yards rushing yet this season but his 4.6 Yards per Carry average through the first four games has been one of the keys to the success of Marc Trestman's offense so far.

Next week the Bears face another big test, this time at home against the New Orleans Saints. The Lions travel to Green Bay and try again for their fist win in the state of Wisconsin since December of 1991.