After Ian Kinsler's two-run homer in the eighth gave the Tigers a three-run cushion, Norris hit Hunter in the ribcage with a 94 mph fastball.
''I don't know if he was trying to hit him or not,'' Detroit manager Brad Ausmus said. ''It looks odd after a home run.''
Hunter yelled at Norris, and as he made his way toward first base, the Tigers outfielder moved slightly in the direction of the mound. That caused both dugouts to empty, and relievers from both bullpens charged toward the infield.
''I'm sorry he didn't appreciate it,'' Norris said, ''but at the same token, I'm trying to throw a ball over the plate and get an out, groundball to third base or something.''
Order was quickly restored before anyone blatantly shoved each other, and no punches were thrown.
Norris (2-3) was ultimately ejected by plate umpire James Hoye.
''Kinsler hits a two-run homer and then the next hitter gets drilled,'' crew chief Bob Davidson said. ''I thought Hoye handled it properly. I think that's what anybody would have done. It's a fastball that drilled the guy in the ribs, and I think Hoye did the right thing. ... As an umpire, it wasn't rocket science. I really think that that was the right thing to do.''
As Norris made his made his way toward the Baltimore dugout, he shouted once more at Hunter, who yelled back.
Hunter watched several replays of the pitch in the Detroit clubhouse before meeting with reporters. Asked if thought Norris was throwing at him, Hunter replied, ''What do you think? I mean, the guy had great control. So what, he all of a sudden lost it?''
Hunter acknowledged that he got swept up by the emotion of the moment, and probably wasn't going to charge the mound.
''It's like a pickup basketball game. There's a foul and two guys argue,'' he said. ''There's a lot of adrenalin going. Once you calm down and think about the situation... it doesn't make sense. I'm too old for this stuff. I've got kids in college. I can't be doing that.''
Rick Porcello (6-1) allowed one run and five hits in six innings, walking none and striking out two in winning his fifth straight start. The right-hander improved to 3-5 lifetime against Baltimore, 1-3 at Camden Yards.
''I managed to get ahead of guys and keep them at bay,'' said Porcello, who left after throwing only 83 pitches.
''He had a little bit of tightness in the side,'' Ausmus said. ''He fought me. He wanted to stay in. It being May, out of precaution I took him out of the game. If he had gone back out there and really injured himself, I would have had trouble sleeping.''
Joe Nathan worked a perfect the ninth for his eighth save.
Steve Clevenger had three hits, including two doubles, and drove in Baltimore's lone run. Clevenger has taken over the starting role at catcher while Matt Wieters (right elbow strain) is on the 15-day disabled list.
Nick Markakis went 0 for 4, ending his 18-game hitting streak. Markakis flied out to center in the seventh with a runner on third and two outs with the Orioles down by a run.
Baltimore went up 1-0 in the second inning when J.J. Hardy hit a two-out single and scored on a double by Clevenger.
Norris was perfect through three innings with four strikeouts. In the fourth, however, Kinsler walked, stole second and scored on a single by Miguel Cabrera. Victor Martinez followed with a double and Austin Jackson added a sacrifice fly.
NOTES: The start of the game was delayed 35 minutes by rain. ... Norris caught a foul ball near the Detroit dugout, darting to his right to catch the popup off the bat of Andrew Romine. ... The Orioles recalled RHP Preston Guilmet from Triple-A Norfolk to strengthen a weary bullpen. He got four straight outs after Norris left ...Ubaldo Jimemez, who starts for Baltimore on Tuesday night, was 0-4 with a 6.59 ERA in April and 2-0 with a 0.71 ERA in May. Drew Smyly (2-2) will start for Detroit. ... Kinsler was caught stealing in the sixth, making Baltimore catchers 4 for 29 in nailing would-be stealers.