Referee Bill Leavy admitted he made a mistake by giving the San Francisco 49ers an extra down that resulted in a touchdown in the second quarter of Sunday's 34-28 win over the Green Bay Packers.

It happened after Packers linebacker Clay Matthews hit 49ers quarterback Colin Kaepernick well out of bounds on a third-and-6 scramble that came up 2 yards short of the first-down marker.

49ers tackle Joe Staley ran into the ensuing fray and grabbed Matthews drawing a penalty for unsportsmanlike conduct that Leavy announced would offset Matthews' personal foul – and then incorrectly replayed third down.

"The down should have counted" Leavy told a pool reporter after the game. "The penalties were both dead ball and they should have offset at the spot where the runner went out of bounds. And it would have been fourth down."

Kaepernick took advantage of the extra snap throwing a 10-yard touchdown to Anquan Boldin that gave the 49ers a 14-7 lead – a four-point swing assuming the 49ers would have kicked a field goal on fourth-and-2.

Packers coach Mike McCarthy dismissed questions about the error as "part of the game" and defended his decision to accept an illegal formation on the previous snap giving the 49ers third-and-6 from the Green Bay 10-yard line instead of fourth-and-1 from the 5.