With two outs in the first inning, Darvish walked A's shortstop Jed Lowrie. Then he gave up a monstrous homer to A's right fielder Brandon Moss. Darvish walked another batter in the first and two more in the second, when the A's scored again to take a 3-0 lead.
"I think mechanically and mentally I was a little bit off today," Darvish said. "I think the slider command was good, but the fastball command was totally off. From there it down-spiraled."
And it didn't stop until the A's hit four home runs -- two against Darvish -- and routed the Rangers, 11-4, to win the series, two games to one, and pull even in the American League West race.
Darvish gave up five runs, matching his season high, and five hits. He walked a season-high six batters and struck out only four, equaling his season low. He lasted just five innings, matching his shortest outing of the season. He gave up a two-run shot to Moss in the first, and a two-run homer in the sixth to A's first baseman Daric Barton, who now has just three home runs over his past 130 games since 2010.
"He didn't have his command, and that can happen," Rangers manager Ron Washington said. "You take the ball enough, that will happen. But nothing that we need to push a panic button on. He didn't have a good day. He was human. Yu is just like everybody else that goes out there and pitches. He can have a day where it don't work, and today was that day."
At one point catcher A.J. Pierzynski came out toward the mound and Darvish appeared to wave him away in frustration. Darvish acknowledged he was frustrated, but said he had no problems with Pierzynski.
"Not at all," Darvish said.
Washington said he wasn't concerned by what he saw during the heat of the game.
"When you're competing, you can't put a certain feeling on something you see out there," he said. "People are competing. I thought nothing of it myself."
Darvish has looked "human" against the A's far more often than against most major league teams. He's 1-5 with a 4.86 ERA in six career starts against Oakland. A's starter Jarrod Parker, meanwhile, improved to 5-1 lifetime against the Rangers, allowing two runs on five hits over six innings to win his ninth straight game. Parker also extended his unbeaten streak to 18 starts, setting an Oakland record.
"He commands the ball, throws it in and out, up and down, changes speeds," Pierzynski said of Parker. "That's why he's had a really good run here for a while. He's been throwing the ball great. He's a good pitcher."
When Darvish left the game, the Rangers trailed 5-2. The A's quickly added four more runs off lefty Robbie Ross, who gave up four runs and hits to all four of the batters he faced in the sixth, including a three-run homer to Josh Donaldson.
"Just wasn't hitting his spots," Washington said. "Wasn't putting the ball where he wanted to. Was leaving it out over the plate."
When the onslaught ended, the A's and Rangers were deadlocked at 80-59 with 23 games left to play, including three against each other at Arlington from Sept. 13-15.
"We lost two out of three. We're even," Rangers second baseman Ian Kinsler said. "There are  games left, and we need to win one more than they win. There's nothing really more to make of the series. They beat us two out of three. We play them again at our place. There are a lot of games in between."
Washington didn't enjoy getting routed, but said he wasn't "disappointed" by the series loss.
"We're still in first place," Washington said. "Of course when you play a series you want to win the series. We didn't win the series. I think we've won series from Oakland before. Then won a series from us. That was it. The day was a better day for them than it was for us."