AP

Seattle Mariners' Richie Sexson watches the path of his second inning home run against the Oakland Athletics at a baseball game, Tuesday, April 3, 2007, in Seattle.

SEATTLE - It's got to be the roof.

That's as plausible a reason as any for the recently marooned Seattle Mariners being 2-0 for the first time since 1996.

Richie Sexson hit his second homer under the closed roof at Safeco Field in two games. Then Yuniesky Betancourt's tiebreaking, two-run shot off Kiko Calero in the seventh inning allowed the success-starved home crowd to follow an outfield sign's urging to "Raise the (Retractable) Roof" by the end of the Mariners' 8-4 victory over the Oakland Athletics on Tuesday night.

The Mariners, who have finished last in the AL West for three consecutive years, have now won as many games in two days against the defending division champion as they did in 19 tries last season.

The win also sent the Mariners to their best mini-start since Ken Griffey Jr. and Randy Johnson were starring for Seattle -- and Alex Rodriguez was a young shortstop and No. 8 hitter.

"No, I did not," Betancourt said when asked if he knew his link to A-Rod. After all, Betancourt was a 14-year-old in Cuba then, still nine years from being smuggled out and eventually into a Mariners contract.

But he smiled at the comparison to the now-superstar Rodriguez -- and again when asked about the rarely closed roof. It was open for 71 of the 81 games last season in this notoriously rainy climate, and was closed for an entire game just six times.

"Yes, when the roof is closed the ball carries much better than when it is open," Betancourt said, through an interpreter. "But it's not really something I pay attention to."

But he noticed in the third inning of the Mariners' season-opening win Monday. With the sun out and Safeco Field's retractable roof open, Betancourt hit a soaring drive to left field that died in the chilly Northwest air. Later, after the roof was closed, Sexson hit a decisive three-run homer that he said would not have gone out earlier.

"Thank God the roof was closed," Sexson said.

Tuesday, with the roof closed just before first pitch on a night in which temperatures dropped toward the 30s, Sexson and Betancourt both homered. Betancourt's came in a four-run seventh off Calero (0-1) and Justin Duchscherer.

Sexson had a two-run drive to the opposite field off Mariners nemesis Joe Blanton in the second inning to give Seattle a 2-1 lead. That gave the usually slow-starting Sexson as many home runs in four at bats this season as he had in 94 at bats while batting .213 last April.

The lead became 4-1 in the fifth. Jose Guillen doubled off Blanton for his first hit as a Mariner. Guillen scored when right fielder Bobby Kielty slid forward on two knees while trying to catch Kenji Johjima's liner. The ball clanged off his leg far into foul ground for a weird double. After Betancourt's fielder's-choice grounder, Ichiro Suzuki singled to score Betancourt.

AP

Seattle Mariners' Yuniesky Betancourt races home against the Oakland Athletics in the fifth inning at a baseball game, Tuesday, April 3, 2007, in Seattle. Betancourt, who was safe on a fielder's choice earlier, scored on a single by Ichiro Suzuki.

Blanton, starting for injured Esteban Loaiza, allowed five hits and four runs in six innings. He struck out seven and walked none. He entered Tuesday 6-1 in eight starts against Seattle, including 4-0 with a 1.55 ERA last season.

"It is ironic that pitching and defense are our strengths -- and the last two days they actually let us down," Oakland manager Bob Geren said, remembering Bobby Crosby's two-error game Monday, including a dropped throw that led to all of Seattle's runs in a 4-0 A's loss.

Crosby -- playing in consecutive games for the first time since last Aug. 20-21 following a stress fracture of a back vertebra -- also threw well wide of first base on a Guillen hard shot that was scored a single two batters before Betancourt's home run.

The A's had three hits, including Milton Bradley's solo home run, in six innings off Jarrod Washburn, who left with a 4-2 lead. They then three hits in the seventh off Julio Mateo (1-0).

Nick Swisher led off the seventh with a single, advanced to second on a groundout and scored on Mark Ellis' two-out single. Jason Kendall, 0-for-7 with three strikeouts to begin the season, then lined a tying double.

Notes: Washburn walked three -- after having walked a total of three in the six previous season debuts of his career. ... This is the first time in the slugging Sexson's 11-season career that he's started a season with home runs in his first two games. ... This is the 11th time in Oakland history the A's have been 0-2, the first time since 1998. The '98 A's finished 74-88, last in the AL West. ... Brandon Morrow, Seattle's fifth overall draft choice last June, pitched a scoreless ninth -- after beginning the inning by walking Swisher and allowing a single by Kielty. Morrow, 22, is the second member of the '06 draft class to debut in the major leagues. Andrew Miller, Detroit's sixth overall pick, played in his first game last Aug. 30 at Yankee Stadium.