He gave it some thought.
"Looking back, I wish I had thrown a slider," he said. "He timed me good. He's a good hitter. He just missed a few pitches before that one."
The Angels had rallied from two runs down to tie it in the top of the eighth behind Chone Figgins' run-scoring triple and Orlando Cabrera's two-out, two-strike RBI single. This little uprising got Jered Weaver even after he'd pitched gamely through seven innings, his only mistakes put in the seats by Jason Bartlett and Torii Hunter.
"It kind of hurts a little bit, because of the way Weaver pitched," said Shields, who fell to 2-3 with the loss. "We came back and tied it in the eighth and had some momentum going.
"The way we've been struggling, to come back and tie it up, we were feeling good about ourselves."
Shields appeared on the verge of escaping a two-on, none-out jam when he wheeled and picked off Nick Punto, who'd singled and reached second on Luis Castillo's walk.
But Bartlett followed with a hit-and-run single through the shortstop hole, putting runners on the corners for Mauer, as pure a young hitter as the game has to offer.
The count went full before Mauer unloaded on that eighth fastball and began running for his life.
The win went to reliever Pat Neshek (5-1) with Joe Nathan notching his 20th save.
Figgins' run-scoring triple drove home Robb Quinlan, who'd hit into a fielder's choice after Maicer Izturis' second hit. Figgins' opposite-field blow, eluding a diving Jason Kubel, came off starter Boof Bonser.
Bonser went a career-best 7 2/3 innings and -- like Weaver, who shaved his ERA to 3.30 -- deserved better. Weaver hasn't allowed more than three earned runs in his past seven starts but has only two wins to show for it.
Cabrera's game-tying single was at the expense of side-winding Neshek, who finished the inning when Mauer threw out Cabrera trying to steal second with two strikes on Vladimir Guerrero.
"You're not going to try to sit back," Angels manager Mike Scioscia said of Cabrera's theft attempt.
It had already been a frustrating day for Guerrero, who broke bats grounding out his first two chances against Bonser and was hitless, his string of homerless games reaching 21.
The Angels haven't gone deep since July 1, when Mike Napoli and Casey Kotchman both homered in Baltimore. That's 14 games without a big blast, four shy of the dubious franchise record.
Weaver had another strong effort go unrewarded. He lasted seven innings and yielding five hits and one walk while striking out two. Twice he walked a tight rope in escaping jams, leaving runners at second and third with nobody out in the second inning, and stranding Garrett Jones at third after a one-out triple in the fifth.
"It's a little frustrating, but what are you going to do?" Weaver said. "Bartlett's [homer] was a curveball I kind of hung out over the plate, and he hit it about two feet over the fence. Hunter, I don't know what to do with him. It was a batting practice fastball down the middle, and he hit it about 469 feet [415 feet by unofficial estimate].
"I felt I threw well. It's one of those stretches. Things aren't really working for us now. It's just a matter of playing ball the way we did in the first half."
It also had been a frustrating day for big brother Jeff Weaver, the former Angels starter losing a 1-0 decision for Seattle against Toronto. That kept kid brother, Jered, in first place in the American League West by one game, in spite of all the recent problems.
After winning 13 of 14 series from May 8-July 1, and leading the AL West by as many as eight games, the Angels have now lost four of their past five series with the Mariners on the move.
The Angels will try to avert a series sweep on Sunday behind southpaw Joe Saunders, who faces Matt Garza.