The Los Angeles Angels had an opportunity to take over first place with a sweep in Oakland just over a week ago.
Instead, it was the Athletics who took control of the AL West by battering Los Angeles pitchers in three straight victories.
Now the Angels are hoping to return the favor in Los Angeles as they open a three-game set between the division's top clubs Monday night seeking their fourth straight win.
Trailing by 1 1/2 games heading into its series against the A's on May 30, Los Angeles (34-28) was dealt its first road sweep of the season and first of at least three games in Oakland since 2004.
The A's (39-24) totaled 26 runs and six homers in that set to build its largest pre-All-Star break division lead since being up 5 1-2 in 1990.
Oakland takes a 4 1/2-game advantage into Angel Stadium and has won five of six meetings this year, totaling 43 runs and hitting .291.
The A's, a baseball-best 22-12 on the road, had another big offensive performance in Sunday's 11-1 victory at Baltimore. They had 10 hits and 11 walks - their most since 2007 - as they claimed a second straight series win on this nine-game trip.
"The walks, it shows we're not getting ourselves out, not beating ourselves," designated hitter John Jaso told the team's official website.
Los Angeles right-hander Garrett Richards (5-3, 3.25 ERA) certainly hasn't been able to solve the A's, going 0-3 with a 7.50 ERA in six career starts - all Angels losses. He failed to get out of the first inning in a 9-5 loss at Oakland on May 30, giving up five runs, five hits and three walks.
Richards bounced back impressively in Wednesday's 4-0 win at Houston, yielding four hits and striking out nine.
"He was (ticked)," manager Mike Scioscia said. "He didn't take that outing in Oakland lying down."
Brandon Moss, who hit a grand slam Sunday, is 7 for 17 with two home runs and three doubles off Richards. Jed Lowrie has gone 3 for 4 with two doubles against Richards this season and is 9 for 19 in his last five meetings with Los Angeles.
Yoenis Cespedes is batting .171 in his last eight games against the Angels, but he has a .343 average with three homers in his last eight overall.
Josh Hamilton has gotten hot for Los Angeles, going 7 for 12 in a three-game sweep of the Chicago White Sox over the weekend. He went 2 for 4 with three RBIs in Sunday's 4-2 win, the Angels' ninth in 11 home games.
Hamilton looks to keep rolling against Oakland's Jesse Chavez (5-3, 3.04). The converted reliever was 2-0 with a 1.89 ERA in six April starts, but he's gone 3-3 with a 4.25 ERA in his last six. He won at Yankee Stadium on Wednesday despite allowing four runs and seven hits in six innings of the 7-4 victory.
Chavez pitched well but did not factor in the decision in his only start against the Angels on April 14, giving up two runs - one earned - and four hits with nine strikeouts over seven innings in a 3-2 road win.
Albert Pujols homered off the right-hander that day and is 5 for 7 lifetime against Chavez but is batting .140 in his last 11 games, including 1 for 11 in Oakland.
Mike Trout is 1 for 6 with three strikeouts off Chavez, but he's hit .350 with two homers, two doubles and five RBIs in four games against the A's this year.