Millwood didn't make it through that inning, as he allowed a two-run homer to Seattle catcher Rob Johnson as part of a 4-1 loss in front of 30,698 at Safeco Field.
Ichiro Suzuki singled off Texas reliever Eddie Guardado to tack on an insurance run three batters later.
Millwood said he felt as strong as he had all game when he went back out to the mound for the seventh inning. Manager Ron Washington said if Millwood hadn't felt up to going back out there, he would have told him.
"Talk to him, see how he felt, said he felt good, and he's one guy that if he's got nothing left, he'll tell us," Washington said. "He told us that he could have went out there for the seventh, so we went with him."
For whatever reason, a Mariners lineup that had struggled to get anything going all night finally found some pitches to hit in the seventh. Ryan Langerhans singled just over the head of shortstop Elvis Andrus to get things started in a 1-1 game, then Johnson -- who was actually trying to get a sacrifice bunt down, but couldn't -- hit a 1-2 pitch into the Mariners bullpen in left field to deliver the fatal blow, his first home run of the season.
The pitch to Johnson -- a slider that Millwood left up in the zone -- was "the only mistake" Millwood made all night, he thought. And the Langerhans single was simply a good piece of hitting.
"It was actually a pretty good pitch," Millwood said of Langerhans' end-of-the-bat base hit. "He just got it over Elvis' head for a base hit. It wasn't a mistake."
New Mariners third baseman Jack Hannahan doubled after Johnson connected, and that was that for Millwood, who saw a pretty good outing end with three consecutive, crucial base hits. He gave up just three hits through his first six innings of work, and allowed only two runners to move into scoring position in that time.
But his counterpart, Jarrod Washburn, was even better. Washburn allowed just four hits over seven innings to earn the win.
"He really did a phenomenal job against a good lineup," Mariners manager Don Wakamatsu said. "He kept them off-balance. He threw several pitches that were right on the black. He didn't throw many pitches in the middle of the plate tonight. He did a phenomenal job."
Texas scored its only run on an RBI double in the third by Ian Kinsler, who stroked a line drive to the wall in left-center to allow Andrus to race all the way around from first base.
They might have had more, if not for a strange play at second base in the seventh inning. Marlon Byrd reached on an error with nobody out and tried to steal second base when Nelson Cruz hit a blooper into center field.
Byrd, head down during the steal attempt, couldn't find the ball immediately and began to retreat to first base. But the ball fell in front of Seattle center fielder Franklin Gutierrez, who fired to second for the forceout.
Instead of having runners on first and second with nobody out, the Rangers had to settle for a man on first with one down. Washburn got a lineout and a groundout to end the inning.
Byrd and Washington both argued that because Byrd had touched second base, a tag was needed to rule him out. But the call was correct -- which Washington and Byrd both acknowledged afterward -- because once a runner starts to go back to first base, he abandons second even if he's touched it.
"That's me not knowing the rules," Byrd said.
Mark Lowe and David Aardsma each threw a scoreless inning of relief, Aardsma closing the door in the ninth to earn his 19th save of the season.
And because the Angels beat the Yankees for the second consecutive night, the Rangers fell a half-game behind them in the American League West standings. Seattle is four games back of first place.
Two at-bats in the seventh were all it took to make Texas a second-place team.
"I thought my stuff was pretty good tonight, for the most part," Millwood said. "Threw the ball where I wanted to. They just put some good swings on the ball there in the seventh inning, and it ended up costing us the game."