Josh Thole and Michael Saunders were the left-handers. Thole's homer came in the third, Saunders' in the fourth.
"I take pride in getting those guys out," Smyly said. "I'm usually pretty effective against them. Tonight I just missed my spot, and they connected."
Josh Donaldson's homer off Smyly came in the fifth.
Not since May 26, 2014, when Smyly pitched for the Tigers, has he struggled so with the long ball. The Athletics hit four home runs off him that night. Donaldson played for the Athletics that night and hit one of those four home runs. Save for that night, Smyly had never given up more than two in a game.
Saunders' two-run homer came in the aftermath of a prolonged review that lasted more than five minutes, but Smyly doesn't know if the delay affected him or not.
"I'm not going to make excuses," he said. "I mean, Saunders hit a 410-foot home run off me. I can't let that happen. I can't give up two home runs to two different lefties in that lineup.
"They have enough hard-hitting righties to where I can't let those lefties beat me. That's how I got beat today."
Added manager Kevin Cash: "[The delay] doesn't help. ... There was a lot of commotion, confusion there. But any time, any pitcher, you don't want to take him out of any rhythm at all. So it's definitely not helpful."
Overall, Cash thought Smyly "was good."
"He just got beat up by the long ball," Cash said. "Two lefties and then, obviously, Donaldson."