BOSTON — The Los Angeles Angels were there for the birth of Big Papi, when David Ortiz went from a mere MVP candidate to the walkoff wonder who made the playoffs his personal playground.

The Red Sox designated hitter homered to eliminate the Angels from the 2004 postseason, later finishing off the Yankees twice on the same calendar day on the way to Boston's first World Series title in 86 years. Over the next two seasons, he hit 101 home runs with 285 RBIs.

Though his power numbers suffered this season as Ortiz fought off a sore knee and shoulder, he set career highs with a .332 average and 52 doubles. After a single and a homer in Boston's 4-0 victory over Los Angeles in Game 1 on Wednesday night, Ortiz is proving that his postseason prowess never left him.

And that can't be good for the Angels.

"David is clutch during the year, he's clutch in the postseason. But this is where he thrives a bit," said Red Sox first baseman Kevin Youkilis, who also homered in Game 1. "We're excited just to have him going on all cylinders right now because that makes for a great October."

Ortiz was coming off a career year in the 2004 regular season when he hit a 10th-inning, game-ending homer to complete a three-game sweep of the Angels in the first round of the playoffs. In Game 4 of the AL championship series against the Yankees, 82 minutes after midnight, Ortiz hit a two-run homer in the 12th inning to help Boston avoid the sweep.

No player had ever had two game-winning hits in the same postseason. But later that same day, Ortiz homered to help send Game 5 into extra innings and then muscled a broken-bat blooper into center in the 14th inning to give Boston the victory.

Ortiz has nine postseason homers in all — tying Jason Varitek for the franchise record — and in 18 playoff games since 2004 he is batting .400, with seven homers and 22 RBIs in 18 games.

After another game-ending homer — against the Angels, of course — near the end of the '05 regular season, Red Sox owner John Henry presented Ortiz with a plaque proclaiming him "The greatest clutch hitter in the history of the Boston Red Sox."

The Angels don't feel like Ortiz is an extra threat under pressure, though. They feel like he's a threat every at-bat of the year.

"I think he performs well in any situation," said Los Angeles manager Mike Scioscia said. "So as far as a clutch hitter late in the game, you're not going to see many guys better than David."

But this year, the mere scent of the playoffs seemed to get Ortiz going. He batted .441 in the last 19 games of the season and .552 with four homers and 10 RBIs in the eight games leading up to October. When the big DH was asked if things were beginning to come around for him after fighting off the injuries most of the year, Varitek interrupted.

"David, I'll answer for you," he said before the regular-season finale. "You came around for us all year."

It's true that Ortiz's overall numbers, despite the home run dropoff, are impressive. He led the majors in on-base percentage and walks, was third in slugging percentage and homers and was fifth in batting average; he was second to Alex Rodriguez in the holy grail of statheads — on base plus slugging percentage — by half of a total base.

But he also went from May 10 to June 4 without a homer, and he had just 14 at the All-Star break, when he revealed to reporters that he had a torn meniscus in his right knee.

"People are just kind of used to seeing you coming through every at-bat, coming and doing some damage. They never sit down and analyze that this is not an easy game to play," Ortiz said after Wednesday night's game. "This is not like a Nintendo game that you can sit down and hit a home run or hit a double or get a hit whenever."

Ortiz received a cortisone shot in the knee as recently as Saturday, and he said it would be something he needed to watch throughout the playoffs. Although he said his knee was feeling better, he seemed more concerned about the sight of "that big old needle coming through your knee."

On Thursday, after taking part in the team's optional workout, he limped through the clubhouse with a bag of ice taped to the knee and flopped on the couch to read magazines.

"David had a monster year. Some of it, a lot of it came late," manager Terry Francona said. "Just the bar was set so high, as far as home runs go. I know he had some shoulder problems. I know he had some knee problems. I also know he played through it, and sometimes that can translate into lower numbers.

"But David's a big leader for us, and when it was time to step up when we needed it, he was right there at the forefront."