The Vikings returned home on Sunday to host division rival Green Bay, one of the hottest teams in the NFL. While they came in as overwhelming underdogs, the Vikings gave Green Bay everything it could handle but came up short in a 24-21 nail-biter

Here are five takeaways from Sunday's loss to Green Bay.

1. Vikings Show Heart, Build Character in a Tough Division LossWins and losses are the bottom line in the NFL and heart alone will not always put you on the right side of that ledger. But that the Vikings battled Green Bay the way they did on Sunday despite the long odds many gave them prior to the game says a lot for Mike Zimmer in his first year as head coach. Green Bay came into Sunday's game on a string of dominant performances but the Vikings gave the Packers everything they could handle all day. Ultimately, the Vikings came away from the game with a loss and fell to 4-7 on the season, but there were many encouraging aspects of the performance that should cause fans to feel optimistic about what this Vikings team can become over time.

2. Secondary Battled Packers Passing GameQuite simply, the numbers Packers QB Aaron Rodgers was putting up heading into Sunday's game were astronomical. His yards-touchdowns numbers the last three games were: 418-1; 315-6; 341-3. While Rodgers was sharp on Sunday and did have two touchdowns with no interceptions, the Vikings secondary brought the numbers back down to earth a little bit. Rodgers finished 19 of 29 for 209 yards and had just two completions of over 15 yards during the game. And on many of the completions the receivers were forced to make contested catches. Green Bay's top two receivers – Randall Cobb and Jordy Nelson – combined for just 126 receiving yards and no touchdown on 17 targets. In terms of most improved areas of the team from last season, the secondary is near the top of the list and Sunday's performance against Rodgers and Co. represented another step forward for that group.

3. Zimmer Showed Aggressive Mentality with 4th-Down AttemptsBy going for it on 4th down early in the 2nd quarter trailing just 7-0, Zimmer showed that he knew it would take touchdowns to beat the Packers, whose average margin of victory through the first 10 games of the season was 22.5 points entering Sunday's game. The Vikings converted both 4th-down conversions – one by penalty and one with a Jerick McKinnon rush – and ultimately scored a touchdown on the drive. The decision to go for it on 4th down and the ability to convert both tries was a great example of a coach showing and building more confidence in his team.

4. Bridgewater Continues to Show PromiseThere was a missed throw here and there and there was an interception on a throw that shouldn't have been made, but at the end of the day it's hard not to be excited about the future for Teddy Bridgewater. The rookie made a beautiful throw – on time and on target with great touch – to help get WR Charles Johnson the first touchdown of his career and tie the game at 7 in the 2nd quarter. Bridgewater tucked the ball and ran for 32 yards on five carries to extend drives. Most impressively, though, Bridgewater led a 4th-quarter touchdown drive that gave the Vikings a chance to tie the game late. Bridgewater drove the offense 79 yards on 13 plays to score on a five-yard connection with former Packer Greg Jennings, and the Vikings were so efficient on the drive that they never had a 3rd-down snap. Also, the Vikings converted a two-point conversion after the score to pull to within three points.

5. Packers Ground Game (including Aaron Rodgers) Made the DifferenceWhen you think about the Packers, you don't think of a productive ground game. But you should. Packers RB Eddie Lacy now has two 100-yard performances against the Vikings this season, and on Sunday he rushed for a season-high 125 yards. More notably, Lacy was Green Bay's closer. Early in the 4th quarter, Lacy had a 15-yard rush to setup a 1st and 10 from the Minnesota 15 and then Green Bay gave him the ball on the next two plays to score the touchdown, with the scoring play coming on a 10-yard shovel pass. Then late in the 4th quarter with the Vikings trying to hold and force a punt to give their offense a shot at a game-winning or game-tying drive, Green Bay gave Lacy four straight carries and he gained 3, 5, 4 and 5 yards to pick up a game-clinching 1st down and run out the clock. Make no mistake, Green Bay's identity is Rodgers and the passing game. But they have a legitimate running game with a reliable, hard-to-tackle running back in Lacy.