Andy Pages went 4 for 4, hitting a pair of two-out homers and driving in another run during a five-run sixth when the Dodgers batted around in taking an 8-3 lead.
Tatis was hit by a pitch from Dodgers reliever Lou Trivino in the third, and Randy Vásquez plunked Ohtani in the bottom half. Both benches were warned and a fiery Roberts came onto the field to complain. He was tossed by third base umpire Tripp Gibson.
Jeremiah Estrada (2-4) took the loss.
In the seventh, Dodgers reliever Matt Sauer (2-1) hit Iglesias in the left hand with a pitch.
Tanner Scott worked the ninth to earn his 14th save.
The Padres pulled to 8-6 on pinch-hitter Trenton Brooks’ two-run homer off Sauer and a bases-loaded balk by Michael Kopech in the seventh.
Key moment
San Diego loaded the bases again in the eighth against Anthony Banda, who induced a foul pop by Luis Arráez to end the inning.
Key stat
Ohtani struck out four times a night after making his pitching debut for the Dodgers, 21 months after having elbow surgery.
