[DonDavis]

In chronological order...
Ross, Az ( accidental )
Puig, LA ( accidental )
Montero, Az ( payback? )
Greinke, LA ( payback? )
Ellis, LA ( accidental )

This goes back nearly 2 years when LA tried to hit Parra and missed. In the same at-bat, Parra then hit a home run and watched it a little too long for LA. Next day starting pitcher Kershaw was yelling from the dugout "I'll see you tomorrow." and the next day, hit Parra. Kershaw was ejected but it's never been over.

Add to that, Az is on a roll beating LA as of late. So, LA is on edge anyway.