OAKLAND -- It's not like the A's scaled Mount Everest on Sunday with a 6-3 win over the Los Angeles Angels.

Kilimanjaro, maybe.

Since the start of the 2011 season, Angels starter Jered Weaver had been as tough as anyone in baseball on the A's, going 8-1 with a 0.87 ERA.

This time around, the A's rocked him for four runs in the third inning and didn't let up the pressure, providing more than enough offense for starter Sonny Gray as Oakland completed a sweep of the three-game series.

Did the A's, who have won five of their first six against the Angels this year, mess with the Angels' minds? It was more like the two-time defending American League West champs certified their authenticity.

Oakland Athletics pitcher Sean Doolittle (62) pitches against the Los Angeles Angels in the ninth inning of their game at O.co Coliseum in Oakland, Calif.,
Oakland Athletics pitcher Sean Doolittle (62) pitches against the Los Angeles Angels in the ninth inning of their game at O.co Coliseum in Oakland, Calif., on Sunday, June 1, 2014. Oakland defeats Los Angeles 6-3 to sweep the series. (Jose Carlos Fajardo/Bay Area News Group) ( JOSE CARLOS FAJARDO )

"It's important for the team to gain confidence," shortstop Jed Lowrie said. He homered and singled and drove in two runs. "Beyond that, as for sending a message, I don't know. I'm too focused on the day-to-day grind of things to analyze that."

Third baseman Josh Donaldson drove in seven runs in the series, two of them with a bases-loaded single in the third inning that broke Weaver's stranglehold on the Oakland offense. Donaldson said the sweep in which Oakland outscored the Angels 26-11 would speak for itself without the A's resorting to playing mind games.

"We played well this series," he said. "We got some timely hits. We pitched well. I think it's just one of those things. We walk out of here feeling good about ourselves."

And how should other teams feel about the A's, now an American League-best 35-22 and 4½ games up on the Angels in the A.L. West?

"Hopefully they'll take us for granted," Donaldson said with a big smile. "Our whole thing is trying to take it one game at a time."

It seems that's wishful thinking on Donaldson's part. Weaver made it clear that any team that underestimates the A's is likely to have egg on its face when the day is done.

"Coming up in the early years, it was a team we looked forward to playing," Weaver said. "You can't take them for granted now.

"They have a good young staff that is throwing the ball well. The guys in the middle of the lineup (are) doing some damage, and guys at the bottom (are) doing the right things to get on base and set things up for the guys in the middle. You remember this feeling."

The Angels still have four months left in the season, so they have to make up only about one game a month to catch Oakland. They can put a dent into the A's in just over a week when Oakland's three-city trip winds up with three games in Anaheim.

For now, however, the A's focus has to be on three games in Yankee Stadium starting Tuesday.

What's clear is that if the A's can hit the heights against Weaver, they shouldn't have inferiority complexes against almost anybody. Weaver was 5-0 with a 0.47 ERA in his last six meetings with Oakland. This time, the A's scored six runs off him, more than any team this year. Oakland's four-run third inning was more runs than Weaver had allowed in any of his previous eight starts.

"We made him work some, but for the first time we squared some balls up," manager Bob Melvin said. "We hit a few balls that found some holes. But he's always difficult; you never know what you're going to see from him. He's as unpredictable as any pitcher in the league."

That kind of unpredictable aura is something that Gray is working on, too. Like Weaver a starter on opening day this year, Gray ran his record to 6-1 with a 2.45 ERA by limiting the damage.

"It seemed like for this series, whenever they had a chance to break through," Donaldson said in speaking of the Angels, "our pitchers would shut them down. Sonny did that today. When we had chances, we got some big hits."

  • The A's, in need of a left-handed bat with Brandon Moss (calf) and Josh Reddick (knee) both ailing, promoted catcher Stephen Vogt from Triple-A Sacramento. Flying in from Fresno, Vogt got to the park less than an hour before the first pitch. "Any time you're called up, it's an honor," Vogt said.

    To make room on the roster for Vogt, the A's sent right-handed pitcher Fernando Rodriguez down despite some outstanding numbers, including a 1.13 ERA and a .143 batting average against.

  • Reliever Ryan Cook, on the disabled list since May 8 with right forearm tightness, will travel with the A's and is expected to be activated before Tuesday's road trip opener.

  • A's infielder Alberto Callaspo was 1 for 9 in his career against Weaver before going 3 for 3 against him Sunday.

  • Donaldson's seven RBIs in the series give him 48 for the season.

    For more on the A's, see John Hickey's Inside the A's blog at ibabuzz.com/athletics. Follow him on Twitter at twitter.com/JHickey3.

    Tuesday's game

    A's (Scott Kazmir 6-2) at N.Y. Yankees (Hiroki Kuroda 4-3), 4:05 p.m. CSNCA