But Quentin charged the mound and sparked a Thursday night melee that could be as costly for the Dodgers as it was temper-igniting.
Greinke, appeared to be injured in a shoulder-to-shoulder hit from Quentin, was escorted off the field at Petco Park by trainer Sue Falsone. He was later diagnosed with a fractured left collarbone.
Matt Kemp and Jerry Hairston Jr. were ejected.
As for the game, the Dodgers won, 3-2, on an eighth-inning solo home run by Juan Uribe.
Quentin, the Padres' left fielder, was hit on the wrist in the series opener by Ronald Belisario and missed the game on Wednesday night.
Quentin also had a personal history with Greinke, as Greinke had hit him twice before.
Then again, a lot of pitchers have hit Quentin. The pitch he took on the left arm from Greinke was the 97th pitch to strike him since the start of the 2008 season, making him the most-hit player in the major leagues in the last five-plus seasons.
When Greinke hit Quentin with the Dodgers holding on to a 2-1 edge, Quentin dropped his bat and glared toward the mound. Greinke appeared to say something to him.
Quentin, who is listed by the Padres at 6 feet 2 and 240 pounds, attacked. Greinke, considerably lighter at 195 pounds, dropped his glove.
A few steps before reaching Greinke, Quentin lowered his left shoulder. Greinke did the same. They crashed. Catcher A.J. Ellis wrestled Quentin to the ground from behind. Shortstop Justin Sellers also flew in.
Players sprinted out of both dugouts. Kemp charged in from the outfield. The bullpens emptied.
As an ejected Quentin was led back to his dugout, Kemp was still screaming at the Padres. Their manager, Bud Black, tried to calm him. So did the Dodgers coaching staff. Tensions appeared to be subsiding when Hairston suddenly sprinted toward the Padres' dugout. As the dugout emptied again, Greinke quietly walked off the field with Falsone.
Kemp and Hairston were ejected. As Kemp turned toward the visiting dugout, Padres players mockingly waved him away.
Kemp turned around. This time, he had to be held back by three players — Beckett, sidelined shortstop Hanley Ramirez and reliever Matt Guerrier.
Greinke will return to Los Angeles Friday to be examined by team physician Neal ElAttrache. There is no timetable for his return.
Greinke said afterward, "I never hit him on purpose. I never thought of hitting him on purpose. He always seems to think I'm hitting him on purpose, but that's not the case."
Of his injury, he said, "It's silly that something could happen like that. It's disappointing."
Dodgers Manager Don Mattingly said of Quentin: "It's just stupid. He should not play a game until Greinke can pitch."
On how Quentin took offense to being hit in a one-run game, Mattingly said, "That's zero understanding of the game of baseball."
Converted starter Chris Capuano entered the game in relief of Greinke, who struck Quentin with his 88th pitch.
The unlikely difference maker was Uribe, who hit a combined .199 with six home runs in his two previous seasons with the Dodgers. Uribe smashed a slider by Luke Gregerson over the left-field wall to put the Dodgers ahead, 3-2. The home run was Uribe's team-leading second of the season.
And it was the second homer of the game for the Dodgers.
Adrian Gonzalez hit his first home run in the first inning, a towering two-run shot that sailed halfway up the left-field stands.