CHICAGO – Boston needs another big comeback, this time just to get out of the first round.

Tadahito Iguchi hit a go-ahead, three-run homer off David Wells after a costly error by Red Sox second baseman Tony Graffanino, and the Chicago White Sox rallied for a 5-4 victory over Boston last night to take a 2-0 lead against the defending World Series champions in their AL playoff series.

“One of the biggest reasons we are here is because of Iguchi,” White Sox manager Ozzie Guillen said. “He moves guys over, he hits home runs, he does everything.”

The Red Sox, 14-2 losers in Tuesday’s opener, took a 4-0 lead in the third, then were shut out on three hits for the final six innings by Mark Buehrle and Bobby Jenks.

Graffanino hit a one-out double in the ninth, but Jenks got the save by retiring Johnny Damon on a foul out to the catcher and Edgar Renteria on a groundout.

Games 3 and possibly 4 in the best-of-five series are at Fenway Park on Friday and Saturday. A fifth game, if necessary, would be at Chicago on Sunday.

After a 19-8 loss to the Yankees in Game 3 of the AL championship series a year ago, the Red Sox won eight straight games to capture their first World Series title since 1918. Boston has won eight of its last nine games when facing postseason elimination.

Wells, who dropped to 10-4 in postseason play, allowed just two hits through the first four innings.

After the White Sox scored twice in the fifth and closed to 4-2,Graffanino let Juan Uribe’s potential inning-ending, double-play grounder go through his legs – bringing up memories of first baseman Bill Buckner’s error on Mookie Wilson’s grounder in Game 6 of the 1986 World Series against the Mets.

“I didn’t get a good read on it. I just took my eye off it. I just flat out missed it,” Graffanino said.

One out later, Iguchi hit a three-run homer to left, giving Chicago a five-run inning for the second straight day.

Carl Everett started the fifth with a single and scored from first when Aaron Rowand doubled into the leftfield corner. Rowand moved up on a grounder before Joe Crede sent an RBI single through the box to make it 4-2.

Uribe’s grounder went right to Graffanino, who played for Chicago’s previous playoff team in 2000, and the ball went through his legs, putting runners at first and third.

Wells then retired Scott Podsednik on a foul pop for the second out but Iguchi, a 30-year-old major league rookie who played eight seasons in his native Japan, connected for the home run.

“If you are going to point a finger, you point it at me,” Wells said.

Buehrle, who started and won the All-Star game for the AL with Boston’s Terry Francona as his manager and Jason Varitek as his catcher, was hit hard by the Red Sox in two regular-season starts, giving up 22 hits and nine earned runs in 13 innings.

He went seven innings, giving up four runs and eight hits. Wells allowed five runs – two earned – and seven hits in 6 2/3 innings.