DENVER —— The Padres are no strangers to the Coors Field effect, that zany byproduct of mountain elevation that turns harmless fly balls into mammoth home runs, quality pitchers into borderline basket cases, and nice, tidy National League baseball into four-hour slugfests.

Entering this season, the Padres had played 75 games at the downtown retro ballpark, winning 35 of them. It could be a while before one is quite as wild as No. 76.

The Opening Day matchup between the Padres and the Colorado Rockies featured eight homers, 12 pitchers, 30 hits, and numerous twists and turns. What it didn't feature was a happy ending for the visitors, as the Rockies rallied for four runs off closer Trevor Hoffman with two outs in the ninth inning to send the Padres to a 12-10 loss before a sellout crowd of 47,661.

"It was like playing on the moon here today," Padres manager Bruce Bochy said.

Said Padres center fielder Xavier Nady, who had two of the Padres' five home runs: "This park is difficult. It wears on you."

Added Hoffman: "Any time a ball gets up in the air, you wonder if it's going to stay in the park."

Charging enthusiastically into a season in which they are expected to strongly challenge for the National League West title, the Padres quickly had some wind taken out of their sails as starter Woody Williams gave up four runs in the first inning and was gone by the fourth.

But the Padres used a power barrage to climb back into the game, and they handed Hoffman (0-1) a two-run lead in the ninth.

The veteran closer allowed a one-out double to rookie Jeff Baker, then retired J.D. Closser to put his team on the doorstep of a 1-0 start to the season. Up stepped pinch-hitter Cory Sullivan, a rookie who had never played above the Double-A level. He promptly lined a double that bounced into the left-field corner despite a fine running effort by Adam Hyzdu, who replaced Ryan Klesko for defensive purposes.

Aaron Miles followed with a single up the middle, his fifth hit of the game, to tie the score 10-10. Clint Barmes crushed Hoffman's next pitch —— a fastball down the middle —— 387 feet to left for a game-ending homer.

Hoffman was denied his 394th save, which would have moved him closer to second place on the career charts. The combined major-league experience of the four Rockies to reach him for hits in the fateful ninth? Fewer than two seasons.

The kiddie corps for Colorado, widely picked to finish in the division's basement, served it well. Barmes had four hits, Baker knocked a homer off Williams in the third, and another rookie, Ryan Speier (1-0), earned the victory by recording two outs in the ninth.

"They're putting on big-league uniforms, and they're playing hard," Hoffman said. "I don't think anybody took them for granted because of their age."

Bochy said Hoffman was having trouble with his famous change-up, but the pitcher couldn't pinpoint any one problem after suffering only his fifth blown save since 2002.

"I probably didn't make the pitches I would like to in key situations," Hoffman said. "It's frustrating to let the first game of the season get away, especially as well as we played to come back. But it's part of the role, and we'll be back Wednesday."

Hoffman at least has a respectable history in Denver, which is a claim that Williams can't make. He entered with a career ERA of 12.81 in four career starts, an ugly number that will only get uglier thanks to Monday's pitching line: six runs, nine hits with no strikeouts in 3 1/3 innings.

In the first start of his return engagement with the Padres after almost four years away, Williams allowed the first five batters to reach base, with the big blow being a 422-foot, three-run homer to left-center by Preston Wilson.

After Matt Holliday singled to right, pitching coach Darren Balsley paid Williams an early visit at the mound and long reliever Dennys Reyes began warming up in the bullpen.

"I just didn't get it going," Williams said. "I was great in the bullpen. If you had told me I was going to pitch like that after the way I threw in the bullpen, I would have said you're crazy."

Said Bochy: "He struggled with his command. He made too many mistakes, and this is a bad park to do that in."

The Padres lifted Williams off the hook by scoring three runs in the third inning and erupting for five in the sixth. Brian Giles and Phil Nevin hit back-to-back homers in the third, and Nady's three-run shot kick-started the rally in the sixth. Ramon Hernandez and Nady also hit consecutive homers in the seventh to provide a 10-8 cushion.

"It was a Coors Field game," Bochy said. "It ain't over until you get that last out. We did a heck of a job coming back, but we couldn't get that last out."

Contact staff writer Brian Hiro at b_hiro@hotmail.com.