With a change of scenery and a change of quarterback, maybe the San Francisco 49ers can still turn their season around. After winning only one of their first six games, the 49ers and backup Troy Smith turned it on in the fourth quarter Sunday to beat the reeling Denver Broncos 24-16 in the NFL's fourth regular-season game in London. "Even though we missed some things early on, I think the rhythm was put in place to make some plays later on," said Troy Smith, who was making his first start as a 49er in place of the injured Alex Smith and the third of his career. "You have to be able to keep your head down and keep even-keeled as a quarterback." Troy Smith completed three long passes in the fourth quarter to get the offense going. Trailing 10-3 and struggling all day, Troy Smith tied the score by rushing for a 1-yard touchdown after completing back-to-back passes to Delanie Walker, the first for 27 yards and the second for 38 following a scramble. Read more: http://scores.espn.go.com/nfl/recap?gameId=301031025