BOSTON — The oozing red sock is now the very symbol of these Red Sox, a rallying cry in the shape of a stitched-up right ankle.

Pitching again through pain and seeping blood, Curt Schilling helped Boston move halfway to snaring its most elusive prize: a first World Series championship since 1918.

Backed by another big hit from surprising Mark Bellhorn and unfazed by a defense that still had trouble getting a grip, the Red Sox beat the St. Louis Cardinals 6-2 Sunday night to take a commanding 2-0 lead.

Jason Varitek’s rare triple, Orlando Cabrera’s single off the Green Monster and a booming double by Game 1 star Bellhorn drove in all of Boston’s runs — enough to offset four errors, including a Series record-tying three by third baseman Bill Mueller.

Schilling showed no ill effects of a bum ankle for six strong innings. Doctors once again used sutures to keep a tendon in place, as they did before he won Game 6 of the AL championship series at Yankee Stadium, and he looked even better this time.

He combined with three relievers on a five-hitter, and kept focused on the main job of shutting down the St. Louis sluggers. Despite Albert Pujols getting three hits, the trio of Larry Walker, Scott Rolen and Jim Edmonds went a combined 0-for-11.

Schilling improved to 8-2 lifetime in the postseason and became the first starting pitcher to win in the Series for three different teams, having also pitched for Arizona and Philadelphia.

Now Pedro Martinez will try to make it a 3-0 lead on Tuesday night when he faces Jeff Suppan in Game 3 at St. Louis. The Cardinals are a perfect 6-0 at Busch Stadium in this postseason, and Suppan outpitched Roger Clemens there in Game 7 of the NLCS.

Red Sox fans might be happy if they did not see their team play again in person this year. Of the 33 teams to open the Series with two victories at home, 28 have gone on to win the championship.

Then again, Boston led 2-0 in its last appearance, winning twice at Shea Stadium in 1986 before losing in seven games to the New York Mets.

Somehow, the Red Sox have won twice despite a pair of four-error performances — the most ever in the opening two games of the Series.

The Cardinals were flawless in the field on a misty, 48-degree evening, yet their baserunning was shaky. A misstep by Reggie Sanders — he stepped over second and had to retreat — cost them a chance to score early.

Matt Morris lost on three days’ rest and the Cardinals lost their eighth straight Series game on the road.

Varitek has hit exactly one triple in each of the last five regular seasons. He picked a good time for a bonus three-bagger.

Morris retired his first two batters before walking Manny Ramirez and David Ortiz on full-count pitches. Varitek then launched a drive to the deepest part of the park, out toward the dirt triangle at the 420-foot mark, and tore his pants with a slide into third.

For the Cardinals, it was a familiar and unfortunate pattern. In their 11-9 loss in the opener, four runners scored after reaching on walks.

Bellhorn made it 4-1 in the fourth. Kevin Millar was nicked by a pitch, Mueller doubled and Bellhorn hit a drive off the base of the wall in dead center.

Ortiz thought he’d added two more runs in the fifth when he hit a shot at Pesky’s Pole in right field. A day earlier, his drive towered above the marker for a three-run homer.

This time, it looked foul to most everyone except Ortiz. He walked halfway to first base, spreading his arms wide and gesturing, showing how the ball hooked around the pole. First-base coach Lynn Jones made sure Ortiz didn’t get too angry and manager Terry Francona talked to the umpires, who huddled briefly before correctly saying it was indeed a foul ball.

Pujols hit his second double of the game and scored in the fourth when Sanders’ two-hopper bounced off Mueller’s chest.

Cabrera’s two-run single made it 6-1 in the sixth. Rolen had a sacrifice fly in the eighth at a time when St. Louis needed a big hit.

The Cardinals threatened in the second when Sanders drew a one-out walk and was running on Tony Womack’s single to right-center. Sanders missed the bag, however, and scrambled back to second.

Manager Tony La Russa called for a double steal, and both runners got a good jump. Only one problem: Mike Matheny hit a line drive right at Mueller, who tagged Sanders for an easy double play.