BALTIMORE — Surprise, surprise: The Baltimore Orioles own the best record in the American League and the Seattle Mariners are in last place.

Sure, the season is only in its second week. Yet the rebuilding Orioles already have plenty to celebrate, most notably their first four-game sweep of Seattle since 1999 and their best start in 10 years.

Aubrey Huff homered to break an eighth-inning tie as Baltimore beat Seattle 5-4 Monday to remain atop the AL East at 5-1.

“As a team, as a whole, we’re playing great baseball right now,” Huff said. “I know it’s early, but we just swept a pretty good team over there. So obviously we’re feeling pretty good, and we just want to keep up the momentum.”

The Mariners and Orioles were involved in one of baseball’s biggest trades during the offseason, a 5-for-1 swap that sent Erik Bedard to Seattle. Baltimore got George Sherrill and Adam Jones, and they both played key roles in the sweep.

Sherrill pitched a perfect ninth inning Monday for his fourth save, his third in the series. Jones had an RBI on Sunday and scored the tying run in the finale to set the stage for Huff’s winning hit.

Bedard, meanwhile, was scratched from his scheduled start Sunday and has pitched in only one game.

Another Baltimore import, Dennis Sarfate, earned wins Sunday and Monday. Obtained from Houston in the Miguel Tejada trade, Sarfate (2-0) retired all four batters he faced Monday before Sherrill entered.

“That’s the best bullpen in the league, in my eyes. When you got guys that can come in for lefties or righties or go two innings or close, it’s fun,” Sarfate said. “It’s fun sitting out there knowing that we have a chance to win every game if the starters keep us close.”

Baltimore’s bullpen has allowed two runs in 21 1/3 innings (0.84 ERA) this season. Seattle relievers yielded six runs over 7 2/3 innings in the four-game series, including Huff’s homer by Eric O’Flaherty (0-1).

Think the Mariners miss closer J.J. Putz, who’s on the disabled list?

“It’s kind of a repeat performance,” manager John McLaren said. “We had a tough time out there. (Huff) had a good pitch to hit and he hit it out. I can’t explain it. Eric is a big part of our bullpen and I don’t know if he has lost his confidence.”

Melvin Mora also homered, and Brian Roberts had three hits for the Orioles, who haven’t been this successful in the early going since a 7-1 starts in 1998.

“Obviously, you want to start out on the right side. I think, right now, winning five out of six games, everyone is contributing, everybody’s getting their feet wet,” said Kevin Millar, hitless Monday but batting .318. “It’s a great feeling for everybody. You start creating some swagger.”

If the city is excited over Baltimore’s fast start, it wasn’t reflected in the attendance. The second-smallest crowd in the 17-year history of Camden Yards, 10,774, came out on a chilly afternoon.

No matter. The Orioles know that no one expects them to win this season.

“That’s why you play the game on the field and not on the stat paper,” Millar said.

Seattle was betrayed by its bullpen, but the offense wasn’t much better. The Mariners went 1-for-7 with runners in scoring position Monday and were 3-for-19 in the series.

Carlos Silva went seven innings for Seattle, giving up four runs and nine hits.

“We have a very good team,” Silva said. “It’s like we need to concentrate a little more. We need to do the little things. Today, maybe if I make better pitches, we win the game. Something is not working right now, but we’re going to get better.”

Ichiro Suzuki opened with his 26th career leadoff homer and singled in the seventh for his 1,600th hit. Raul Ibanez homered and drove in two runs, but it wasn’t enough to overcome the Orioles’ surprisingly robust attack.

Orioles starter Daniel Cabrera overcame a shaky start — he gave up first-inning homers to Suzuki and Ibanez — to pitch six innings of five-hit ball. The right-hander allowed four runs, walked four and struck out five before leaving with the score tied 4-4.