Green Bay, Wis. (WHBL-Learfield) - The Green Bay Packers are still a game behind first-place Chicago in the N-F-C North with four left. The Packers had a dominating second half yesterday to beat San Francisco, 34-to-16 at Lambeau Field -- while the Bears kept the division lead with a 24-20 win at Detroit. The Packers led by one at the intermission. They broke the game open early in the second half with a 61-yard pass from Aaron Rodgers to Donald Driver, who broke several tackles along the way. It was Green Bay's first cold-weather game of the year, with temperatures in the 20's and a steady wind at just over 15-miles-an-hour. Rodgers threw for 298 yards and three touchdowns, the other two to Greg Jennings. John Kuhn scored the Packers' other T-D on a one-yard run. Rookie James Starks had 18 carries for 73 yards in his Packer debut. The Elias Sports Bureau said it was the most yards by a Green Bay rookie in his first game since 1948. All told, the Pack had 136 yards on the ground. They had 410 total yards to 269 for San Francisco. The Packers converted 9-of-15 third downs, while the 49'ers only converted on 3-of-12. And Green Bay held the ball 14-and-a-half minutes longer. Jennings was the Pack's leading receiver with six catches for 122 yards. Green Bay defensive end Cullen Jenkins aggravated an injured calf near the end of the game. Vernon Davis caught four catches for 126 yards and the only touchdown for San Francisco, who dropped to 4-and-8. The Packers have won four-of-their-last-five to improve to 8-and-4. They'll play at Detroit next Sunday.