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.
When he spoke with reporters Thursday, Matthews wouldn't comment on speculation he would be disciplined for his hit on Kaepernick, who threw for a career-high 412 yards and three touchdowns in the game.
"I'm not really going to discuss all that right now, but on to the next game," said Matthews. The Packers host the Washington Redskins on Sunday.
Matthews said he was fined by the NFL one other time for a face-mask penalty he had against Chicago Bears quarterback Jay Cutler in 2010, the linebacker's second pro season.
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.