SEATTLE -- Giants' outfielder Jason Ellison was inserted into the lineup Sunday to provide -- as manager Felipe Alou said, "energy " -- and the leadoff hitter did just that, hammering a homer in the first inning.

But San Francisco's offensive level sagged disturbingly after that, as Seattle's 42-year-old left-hander Jamie Moyer handcuffed the Giants through the next seven innings in the Mariners' 5-1 victory at Safeco Field.

It meant a three-game sweep for Seattle in the Interleague series and the Giants' seventh loss in the last nine games. In 27 innings, San Francisco was held scoreless in 21 frames, mustering only six runs overall, and hit a mere .180 overall.

Worse, the 34-35 Giants have fallen below .500 for the first time since May 15.

"We didn't do anything," said Alou. "The last couple games we didn't give ourselves a shot -- or they didn't give us one."

While there may be a pretty detailed "book" on Moyer by now -- what he throws, how he throws, where he throws -- but after Ellison jumped on a 3-1 fastball for his second career leadoff blast, the left-hander proceeded to befuddle and confuse.

"That guy is notorious for throwing the way he did today, and he was on pretty well, getting pitches off the plate -- it made it tough on us," said Ellison, appearing in Seattle for the first time since attending Bellevue Community College.

Ellison, like Alou and everyone else, has no explanation for what ails the club's offense at the moment. The Giants pounded the Diamondbacks for 20 runs over three games, yet fizzled dramatically here.

"We're just not putting things together," said Ellison. "We're getting people on and hitting in double plays -- I was guilty of that today. We just haven't been able to get anything going."

Slugger Barry Bonds, who hit his 718th career home in Friday night's game, struck out three times on Sunday -- twice by Moyer and in the ninth inning by J.J. Putz. It was the first time he's done that since June 12, 2003, against the Chicago White Sox facing Bartolo Colon.

Bonds said no one's panicking at this stage. The season won't really kick into gear until August, the first quarter pole before the crucial stretch run.

"They all pitched well here, and Jamie [Moyer] did a great job," Bonds said of the Seattle hurlers. "He's a good pitcher. When you're good, you're just good and you just accept it."

"I'm not worried in June," Bonds said of the Giants' offensive troubles in a tight National League West division. "We just have to stay in there. As long as you stay close, anything can happen over the last two months."

The Giants, Bonds says, keep falling back, but recalled last season when they had a rough first half but zoomed into contention and stayed there until the final week.

"We've always been a late-bursting team -- we've never been a team to go out in front since 1993 when the Braves caught us," Bonds said. "We've always been a second-half team. We don't panic. We've never panicked."

The Giants' cause was hurt Sunday when outfielder Moises Alou, hitting .311 overall with nine homers and 31 RBIs, was pulled moments before game time with a lower back spasm.

The 41-year-old Alou was on the disabled list with a severe ankle sprain for 4 1/2 weeks and was feeling OK until he began packing to leave the team hotel.

"I felt something, like somebody stabbed me in the back," said Alou. "I could barely move. I can't bend down. I had this before, but I knew it would go away -- this didn't go away."

Alou took a pain killer and didn't hit or exercise before the game, but was unable to compete.

For Giants' starter Jamey Wright, it was another tough defeat. The right-hander is second on the club in wins, third in innings pitched and second for 11 six-plus-frames starts.

But Wright has a five-start winless stretch. On Sunday, he allowed four runs over 6 2/3 innings, including a fifth-inning solo homer to Adrian Beltre and a dicey three-run third when he tried a "kick-save" on a hot grounder by Beltre that trickled safely into short left field, igniting the rally.

"I tried to deflect it to [shortstop Omar Vizquel] -- he's supposed to be right where I deflected it," said Wright. "It was a tough one. Even Beltre hit a good pitch down, the one I usually get 10 grounders a game, but he muscled it out. I couldn't believe it."

With his luck, without Wright's deflection, the ball probably would have rifled into center field.

"I've got to keep plugging away and get ready for the next one," said Wright. "It's not going to get any easier, with Anaheim, Oakland and Texas coming up -- three pretty tough teams. I guarantee you they won't feel sorry for us."