Brett Anderson has surprised even his own manager with how well he's pitched since returning from Tommy John surgery.

It's unlikely anything shocks the Athletics when it comes to how good Jered Weaver is against them.

Anderson looks to help Oakland complete its first four-game sweep in Anaheim in nearly 11 years against Weaver and the Los Angeles Angels on Thursday.

Oakland continued its stellar play with a 4-1 victory Wednesday night, its sixth straight win overall and 12th in a row on the road. The road streak matches the 1971 team for the longest since the club relocated from Kansas City to Oakland in 1968. The franchise record is 14 in a row, set in May 1931.

A.J. Griffin went eight scoreless innings and Yoenis Cespedes homered, as Oakland (82-60) remained three games behind AL West-leading Texas. The Athletics, winners of 21 of 26, have a two-game lead for the top wild-card spot.

Los Angeles (77-66), which has lost three straight following a six-game win streak, has dropped 3 1/2 behind the second wild card.

"Those guys have been pitching great all year, and this series they matched up well against us and are doing a good job," Angels manager Mike Scioscia said. "A week ago we were playing great baseball, and right now we've hit a little bump in the road."

Hoping to avoid their first four-game home sweep at the hands of the Athletics since Oct. 4-7, 2001, the Angels will have Weaver (16-4, 2.86 ERA) on the mound for the first time since Sept. 2.

The right-hander is 5-1 with a 1.02 ERA against the Athletics over the last two seasons. Weaver pitched a four-hitter in a 4-0 win in Oakland on Aug. 6, improving to 2-0 with a 0.38 ERA in three meetings this year. He's struck out 19 and walked three in those outings.

However, after struggling through his previous five starts with a flare-up of biceps tendinitis, Weaver's turn was skipped last week.

"Especially this time of year, you don't want to take any time off," Weaver, who completed a successful bullpen session Monday, told the Angels' official website. "I'm looking forward to getting back out there."

His return sets up an intriguing matchup against Anderson (4-0, 0.69), who is making his fifth start of the season after being sidelined more than a year following Tommy John surgery.

Anderson continues to put up impressive numbers since returning. He gave up one unearned run over six innings in a 6-1 victory at Seattle last Saturday.

"I think it's been more than we could ever expect,'' manager Bob Melvin said of Anderson's recovery. "To sit here and say he's 4-0 at this point coming off that is pretty terrific."

Facing the Angels for the first time this year, Anderson is 1-2 with a 3.63 ERA in six career starts against them.

The left-hander will look to follow Griffin's outstanding start, which lowered the rotation's ERA over the last 18 games to 2.73.

Anderson might not have much room for error given the way Weaver has pitched against the Athletics. However, the Angels ace is 1-3 with a 6.14 ERA in his last five starts overall.

Weaver may need to be on top of his game with his teammates struggling to generate offense in this series. The Angels have scored seven runs and hit .216 in the first three games after averaging 5.7 runs while winning 15 of their previous 18.