San Francisco kept Detroit in the game with missed opportunities, then made just enough plays for a rare two-game winning streak and its first road win. RB Frank Gore set a franchise record with 148 yards rushing in the first half and scored on a 61-yard run before leaving with a concussion. San Francisco led 13-3 at halftime after scoring on three of its first four drives, wishing it had a bigger lead after out gaining Detroit 247-102 yards and recovering a fumble without giving up a turnover. The 49ers had chances to go ahead big in the third quarter because Detroit had two turnovers on its first three plays, but they came away with only a field goal and a 13-point lead. Gore then caught a 7-yard pass, wobbled off the field and didn't return. QB Alex Smith's fumble midway through the third quarter set up a score that helped the Lions get back in the game. The 49ers drove down the field to set up K Joe Nedney's fourth field goal, a key score because it made Detroit go for a TD instead of kicking a tying field goal late in the game. S Keith Lewis intercepted QB Jon Kitna's pass at the 49ers' 2 with 2&#189; minutes left and San Francisco now 4-5 picked up the one first down it needed to seal the game, winning consecutive games for the second time since 2003. RB Frank Gore finished with career-high 159 yards rushing and San Francisco's QB Alex Smith was 14 of 20 for 136 yards with a fumble. WR Arnaz Battle caught six passes for 55 yards, and converted a third-and-4 on the final drive to allow the 49ers to run out the clock. The 49ers' defense again came up huge, allowing only 273 total offensive yards and forcing 4 turnovers. LB Brandon Moore was yet again the story, leading the team with 9 tackles, 2 sacks and forcing 2 turnovers. With the win, the 49ers advanced to 4-5.. How many points did the 49ers lead by at halftime?