They're on a winning streak, they've won each of their games in the streak by double-digit margins and have one of the most athletic quarterbacks in the NFL.The San Francisco 49ers? Yes. But it also describes the Carolina Panthers, who come to Candlestick Park Sunday to face the Niners.The Panthers (5-3) have a four-game winning streak and a hot quarterback in Cam Newton. During those four games, Newton has a 109.8 passer rating – fourth best in the league – and has rushed for 128 yards and three touchdowns. Newton is big, strong and fast, but he also has a cannon arm capable to completing long passes against the 49ers secondary."Man, we watched him on film and he can throw the ball," 49ers linebacker Patrick Willis told Eric Branch of the San Francisco Chronicle. "He doesn't have to have his feet into it and he can sling it."Newton also has four receivers with more than 350 yards receiving in Steve Smith, Greg Olsen, Brandon LaFell and ex-49er Ted Ginn Jr. Plus running backs DeAngelo Williams (519 yards rushing) and Mike Tolbert (206 yards) create a balanced attack.The Panthers are averaging 25.5 points per game (12th in the NFL) and 130.1 yards per game rushing...