The beanball ranks as sport's most visible, if not volatile, form of retaliation. Witness Tuesday night's scene at Dodger Stadium, where Manny Ramirez got hit by a pitch, teammate Guillermo Mota responded by plunking Brewers slugger Prince Fielder, and Fielder tried to storm the Dodgers' clubhouse after the game. But baseball doesn't own the art of revenge. Consider these examples:
Funny that the poster boy for payback in the NFL is a wide receiver.
During a game at Jacksonville last season, Pittsburgh's Hines Ward leveled Jaguars linebacker Mike Peterson with a block. Ward was later disciplined by the league, but, at the time it was Jacksonville defensive end Paul Spicer who drew a penalty for shoving Ward after the play.
There was also talk of Cincinnati's retaliating against Ward after his hard block on another linebacker, Keith Rivers, which resulted in a broken jaw for the rookie and former USC star.
Anyone who says basketball isn't physical must have missed the Western Conference semifinal between the Lakers and Houston.
The Rockets won the first game of the series with a tough brand of play. Late in Game 2, Houston forward Luis Scola fouled Lamar Odom and words were exchanged.
The next time Houston had the ball, Lakers guard Derek Fisher threw an elbow and leveled Scola as he came up to set a screen near the top of the key. Fisher was ejected and suspended for the next game, but his response helped turn the series in the Lakers' favor.
It was the head butt heard 'round the world.
With the score tied, 1-1, in the 2006 World Cup final, French captain Zinedine Zidane slammed his bald pate into the chest of Italian defender Marco Materazzi. Zidane immediately drew a red card and was ejected.
The superstar claimed that Materazzi had insulted his mother, an accusation the defender denied. Either way, France could have used Zidane's accurate foot, losing the game in a shootout.
It might seem risky to retaliate at high speed, but that doesn't stop NASCAR drivers from getting hot under the hood.
At a race in Phoenix this spring, Casey Mears tapped Dale Earnhardt Jr. into the wall. Earnhardt caught up to him on the cool-down lap and nudged his rear fender, which caused Mears to spin out.
The situation continued on pit road, where Mears gave Earnhardt something more than a gentle tap from behind. Both drivers were placed on probation.
It's a story as old as the game itself: Two minutes into a nationally televised game at Wrigley Field last season, Chicago defensemen Brent Seabrook blasted Detroit's Dan Cleary along the boards, sending Cleary head-first into the Chicago bench.
The check came in response to Cleary's hit on Blackhawk star Patrick Kane a few nights earlier.
Though retaliation is woven into the fabric of hockey, NHL officials have become concerned about a recent trend that suggests players are retaliating after clean, hard hits.
A league study suggested that more than 20% of fights appear to be retaliatory.