Normally automatic -- he had thrown 15 scoreless innings at Yankee Stadium to open his Major League career -- Chamberlain never appeared completely comfortable as he inherited a lead from starter Andy Pettitte, who threw 6 1/3 innings of two-run ball before handing off to Kyle Farnsworth for the seventh inning.
Fidgeting often, Chamberlain worked to a two-strike count on leadoff batter Grady Sizemore before losing him on a walk, and after a sacrifice bunt, Chamberlain lost Jhonny Peralta on a full-count fastball to put the tying run aboard.
"I was just kind of out of whack," Chamberlain said. "I just couldn't get out there, and my hands were separating late. It's going to happen. Nobody's perfect."
A flyout followed a visit from pitching coach Dave Eiland, but with closer Mariano Rivera stirring in the bullpen, Chamberlain left an 0-1 fastball up and over the plate. Dellucci stepped in for Franklin Gutierrez and turned on the heater for his 10th career pinch-hit home run, stunning a Yankee Stadium crowd of 50,713.
"People might think he's somewhat invincible when he gets on the mound," Yankees manager Joe Girardi said. "He's human just like anyone else. He'll learn from this, and it'll make him a better pitcher. In the long run, this will make him a better pitcher. It'll make him tougher inside, and it's all part of maturing."
The shot hit Chamberlain for his first career blown save and, eventually, the phenom's second Major League loss. Later, Girardi would call the home-run pitch a mistake but say the real issue was with the walks to Sizemore and Peralta, which set up the game-changing inning.
"It's over with," Chamberlain said. "It [stinks] when it happens, definitely, but you understand that it's part of the game."
After the inning, Chamberlain sat in the Yankees' dugout with a towel resting over his head. The home run snapped a string of 11 2/3 scoreless innings pitched by the Yankees' bullpen dating back to April 25, including Farnsworth's two-thirds of an inning on Tuesday.
"He'll bounce back," Girardi said of Chamberlain. "Part of you wants to go give him a hug and tell him it's going to happen. You're not going to be perfect the rest of your career. Joba is strong inside, and I know he'll come back and he'll be very good again."
"As a pitcher, there's no pitcher that hasn't gone through that process. Everyone goes through that process. The biggest thing is how you bounce back. He's going to be fine."
-- Mariano Rivera, on Joba Chamberlain
The loss for Chamberlain was striking, given the circumstances -- Tuesday's game featured a pitching rematch from Game 2 of last year's American League Division Series, the infamous "midge" game at Cleveland.
In that affair, with Pettitte and right-hander Fausto Carmona doing battle, Chamberlain's wildness cost the Yankees a lead in a game they would lose, sending the series back to New York down, 2-0. Rivera said that he sees plenty to suggest that the 22-year-old can handle the setbacks.
"People can create whatever they feel like," Rivera said. "As a pitcher, there's no pitcher that hasn't gone through that process. Everyone goes through that process. The biggest thing is how you bounce back. He's going to be fine."
Carmona wasn't at his October sharpest on Friday, working just five innings in a three-run effort, and New York took the lead in the fourth with the help of a pair of long-struggling Bombers bats.
Jason Giambi -- batting .150 coming into the game -- ripped a run-scoring double to the gap in left-center field. Later in the same frame, Robinson Cano -- straggling along with a .154 mark -- shot a bouncer through the left side, bringing home Giambi.
But the Yankees, as they'd later lament, might have had more. Sizemore raced into the left-center-field gap to snare a Johnny Damon line drive with two outs in the fourth inning, stranding Wilson Betemit and Jose Molina aboard. Damon said he originally thought the ball would fall in.
"What I said was, 'No way,'" Damon said, "and then the ball hung up and gave him plenty of time to track it down."
"That was a pretty big play he made," Girardi added. "We were going to tack on some more runs there. Grady Sizemore is quite a defender. He laid out completely to make that play, and if that ball gets by him, we might have a triple. Who knows how many runs we'd score?"
Hideki Matsui extended his hitting streak to a career-high 15 games with his single to load the bases in the first inning, part of a three-hit evening. The Yankees brought the first run in a batter later, when Giambi hustled out a fielder's choice, allowing Derek Jeter to cross.
Cleveland briefly took a lead off Pettitte in the fourth, when Jhonny Peralta connected on his sixth home run of the year, a two-run shot to right-center, but the left-hander was otherwise strong over a 104-pitch (65 for strikes) outing.
He earned a standing ovation as he trotted off the mound in the seventh inning, limiting the Indians to two runs on five hits, walking one and striking out six.
Pettitte left in line for the victory, which would have been his first against the Indians in New York since June 16, 1996, a span of nearly 12 years and Pettitte's longest drought without a home win against any AL opponent.
By the time Chamberlain stepped on the rubber in the eighth, Pettitte said he was already wandering the clubhouse. He later wondered if Chamberlain has spoiled not only Yankees fans, but also the players, into expecting perfection.
"He's done it so much that you sit here and you don't think he's going to give up anything," Pettitte said. "That's the big thing, to see how you bounce back. He's special. He's going to obviously do the job for us more times than not."