The Mariners can record a season-high fourth straight victory by handing the A's a fifth consecutive home defeat Tuesday night.
Seattle (15-15) averaged 2.3 runs during an eight-game skid that it's followed with a stretch of eight wins in 10 games while scoring 5.5 per game. The Mariners dropped four of their first six with Oakland (19-13) this season, but improved to 5-1 on this trip with Monday's 4-2 win.
Rookie outfielder Stefen Romero hit his first career homer and Chris Young allowed two runs over six innings as the Mariners handed Oakland its third loss in four games overall and fourth straight at the Coliseum, where it last dropped five in a row May 22-27, 2012.
Romero went 8 for 38 (.211) in 14 games last month, but is 6 for 17 in four May contests. The home run marked the third straight game Romero has recorded an extra-base hit after doing so three times in his first 15.
"Fortunately it got out," he said. "Just not having done it this year, it's pretty sweet to get that one out of the way."
The right-hander will try to continue his surprising start that began April 3, when he allowed one earned run in six innings of a 3-2, 12-inning home win in his first career start versus Seattle.
Chavez yielded five runs in five innings of a 12-5 victory at Houston on April 25, but bounced back to give up one hit and strike out eight over seven scoreless frames of a 12-1 win at Texas on Wednesday.
"We've seen that game a few times already this year," said manager Bob Melvin, whose team is 6-0 with Chavez on the mound. "Quality stuff all the time. Mechanics are terrific. Keeps guys off balance."
Roenis Elias (2-2, 3.09) allowed a run and two hits in five innings in his major league debut against Chavez and the A's last month. The left-hander has given up one earned run in half of his six starts, including Thursday along with 10 strikeouts over a season-high seven innings in a 4-2 victory at Yankee Stadium.
"He's not a typical lefty who tries to trick you," New York star Derek Jeter said. "He gets it up there pretty good."
Oakland utility infielder Nick Punto is the only current member of the A's roster who got a hit against Elias last month.
With a two-run homer Monday, Oakland slugger Brandon Moss is 3 for 7 in two games after going 1 for 13 in his previous six contests.
He's 14 for 47 (.298) with seven homers in his last 14 games against Seattle.