LOS ANGELES -- Aaron Cook couldn't make his sinker sink, couldn't make his best pitch miss bats, couldn't keep the ball on the ground, and knew he was in trouble from the start.

Four shaky innings, three home runs, and one forgettable outing later, Cook was gone from the game and the Rockies had a glimpse of the way the Dodgers expect to win the National League West.

Cook surrendered Manny Ramirez's first two home runs of the season and the first of two home runs which Andre Either hit, as the Dodgers won the second game of the series, 9-5, before 36,795 Saturday at Dodger Stadium.

Cook's outing was worrisome for the Rockies. He recorded six fly ball outs in his four inning stint and it was evident from Ramirez's hard-hit rising line drive to left-center field on a full-count pitch in the first inning that Cook was in for a difficult outing.

It wasn't only Ramirez's home runs. Cook gave up three soft singles, all on shallow flares to the outfield, the first time through the lineup.

"Somebody in the dugout made a comment that Cook's not used to seeing this many fly ball outs," Ethier said. "Obviously we took advantage of a guy whose stuff wasn't working well today."

Cook couldn't compete without his sinker.

"The ball looks flat coming out of my hand," Cook said. "It doesn't mean velocity, it means rotation and explosiveness aren't there."

Ramirez tagged Cook again in the third inning, pulling a pitch hard down the left-field line. It was the 54th multi-home run game of his career.

Ethier provided the final blow, hitting a three-run home run in the fourth inning that extended the lead to 5-0.

"Fly balls are very uncharacteristic for Cook," Hurdle said. "His priority every game is to establish his sinker. That didn't happen today and there wasn't a Plan B or a Plan C with any consistency or sharpness."

Cook (0-1) said he knew he made a mistake to Ramirez on the first home run, but felt he located the second home run pitch exactly where he wanted it. He felt the best pitch he threw in the game was the sinker he used to strike out Ramirez in the fourth inning, which ended up being his last pitch of the afternoon.

"Other than the [strikeout] pitch I threw to Ramirez, I don't feel like I commanded anything," Cook said. "The first pitch Manny hit was a bad pitch and the second pitch I thought I got exactly where I wanted. He's just a good hitter."

Cook made it past the third inning, eclipsing Jason Jennings' career Rockies mark of 941 innings, but he couldn't make it into the fifth inning. His final line wasn't one for the scrapbooks: four innings, five runs, eight hits and two walks. His ERA rose to 10.22.

Cook, who won 16 games in 2008, has pitched into the sixth inning in only one of his first three starts in 2009. In the fourth inning, he gave up a leadoff single to Brad Ausmus after a tough at-bat. With two out, Cook walked leadoff hitter Orlando Hudson and fell behind 3-1 to Ethier, who drilled the next pitch into the right-field stands.

"[Cook] didn't want to walk Ethier," Hurdle said. "It caught too much of the plate. That ball Ethier hit was halfway up the grandstand."

Cook struck out Ramirez to end the fourth inning, his final batter of the game, but his best pitch came too late.

"I'll sit back down, look at some video," Cook said. "Physically this is the best I've felt in a long time."

Dodgers right-hander Chad Billingsley (3-0) started with five scoreless innings, pitching out of jams in the second and third innings. Those two innings inflated Billingsley's pitch count and helped the Rockies reach him in the sixth inning.

Trailing 5-0, Sean Smith drew a leadoff walk and Todd Helton followed with a single. Brad Hawpe delivered a one-out, two-run triple and scored on Ian Stewart's sacrifice fly to cut the lead to 5-3.

The Rockies squandered another scoring opportunity in the seventh inning. Rookie Dexter Fowler singled, stole second and pinch-hitter Jeff Baker walked.

The Dodgers brought in left-hander Will Ohman to pitch to lefty Todd Helton, who hit a soft liner off the end of the bat that Dodger third baseman Blake DeWitt caught and threw to second, doubling off Fowler to complete the inning-ending double play.

Ethier's second home run, a seventh-inning leadoff shot against Alan Embree, started a four-run seventh inning that put the game out of reach.

Ian Stewart hit a solo shot in the eighth, but by then, it was too late.

Hurdle said the Rockies are pressing offensively. Colorado had only seven hits.

"We have some of that going on," Hurdle said. "We have some guys hitting the harder, faster, quicker button and we talked about it backing off, getting a single and hitting it where it's pitched. Sometimes it's the only way to get their attention."