GREEN BAY, Wis. -- Green Bay linebacker Clay Matthews was fined $15,000 for a hit on San Francisco quarterback Colin Kaepernick during the teams' season opener.

According to the NFL, Matthews was fined "for striking an opponent late."

Matthews drew a personal-foul penalty in the 49ers' 34-28 win Sunday after he tackled Kaepernick out of bounds deep in Green Bay territory during the second quarter.

A fracas between players from both teams followed on the sideline when Matthews and 49ers left tackle Joe Staley began pushing and shoving.

Staley received an unsportsmanlike-conduct penalty. That offset the late-hit call against Matthews, resulting in a replay of third down at the Packers' 10-yard line.

Kaepernick then connected with Anquan Boldin for a 10-yard touchdown pass to put the 49ers ahead 14-7.

The announcement of the fine came Friday afternoon after the Packers completed their post-practice obligations with the media.

Besides Matthews, the NFL fined Boldin $7,875 for a late hit on Packers cornerback Jarrett Bush in the third quarter of Sunday's game and fined 49ers linebacker Ahmad Brooks $12,750 for a roughing-the-passer call, the league said.

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