Muhammad Ali and a starry crowd watched as the Yankees beat Boston for the first time in nine games this season, with Posada and Melky Cabrera hitting three-run homers in New York's 13-6 victory on Thursday night.
"We are playing a lot better than we started playing at the beginning," Posada said. "We are pitching better and we're doing a lot of things well on the mound and at the plate. Hopefully we can carry on and do what we did today."
Posada had three hits and three RBI, saluting Munson with the type of all-around game that the former Yankees catcher was known for before he died in a plane crash on Aug. 2, 1979. Posada said he had never put Munson's number on his mask before.
"Thurman was special to me," he said. "Just wanted to tell everybody that I was thinking about him today."
Johnny Damon and Mark Teixeira also connected for New York, which ended a nine-game skid against Boston dating to last season. It was the Yankees' longest drought in one of baseball's most heated rivalries since they lost 17 straight from Oct. 3, 1911, to July 1, 1912.
Damon's third-inning shot off John Smoltz (2-5) was his third in three days, Cabrera and Posada went deep in New York's eight-run fourth and Teixeira delivered the final blow with his 28th homer leading off the seventh.
"That's an unforgiving lineup in an unforgiving ballpark," Red Sox manager Terry Francona said.
Despite a career-high seven walks, Joba Chamberlain (8-2) lasted five innings to win his fourth consecutive start.
"You've got to give credit to the offense for picking us all up and doing the things that they've done great since the second half," he said.
Casey Kotchman hit a two-run homer in his first start for Boston and Dustin Pedroia also went deep. David Ortiz went 0 for 5 and was booed lustily in his first game at Yankee Stadium since he said the union confirmed his name was on the list of 104 major leaguers who tested positive for performance-enhancing drugs in 2003.
The AL East-leading Yankees increased their lead over Boston to 3½ games with their fourth consecutive win. Red Sox ace Josh Beckett is scheduled to face A.J. Burnett on Friday in the second matchup of the four-game series.
Banged-up Boston played without All-Star outfielder Jason Bay and shortstop Jed Lowrie departed in the fourth inning with an irritated left forearm. Bay re-injured his right hamstring Wednesday night and is expected to miss at least the first two games against New York, leading to a rare start in left for Gold Glove first baseman Kevin Youkilis.
Kotchman's first homer since he was acquired from Atlanta on July 31 gave the Red Sox a 3-1 lead in the fourth but Smoltz quickly gave it away in the bottom half, looking nothing like the big-game pitcher Boston hoped it was getting when it signed him in the offseason.
"I'm not doing it right now," Smoltz said. "I'm a big enough man to stand up here and say I'm not doing it. Time may not be on my side if this continues. I've been here before, but not like this."
The Yankees' first five batters reached in their biggest inning since they scored nine runs in the fourth against the Mets on June 14. Cabrera belted a 1-2 pitch from Smoltz into the second deck in right to give New York a 5-3 lead and Posada capped the scoring with a shot to center off Billy Traber.
Smoltz (2-5) was tagged for eight runs and nine hits in 3 1/3 innings, sending his ERA to 8.33 for his eight starts this season. It was his most runs allowed since he gave up eight in a no-decision with Atlanta on May 28, 2006, at Wrigley Field.
"I'm frustrated, all the way around," he said. "Felt good coming in, didn't make pitches."
Chamberlain gave up four runs and six hits. He hasn't lost since June 18 against Washington.
A sellout crowd of 49,005, the largest at New York's plush new ballpark, delivered a loud chorus of boos when Ortiz came up with two outs and two on in the first. A fan sitting in left field held up a sign with an asterisk. Ortiz then flied out, leading to an even louder cheer.
The only testy moment came in the eighth when Mark Melancon threw a pitch over the head of Pedroia, then hit the Boston leadoff man.
Posada walked with Pedroia down the first-base line and Francona came out to talk with plate umpire Derryl Cousins. Francona said Cousins issued a warning against further trouble.
"I don't know why they're throwing at me, if they were. It's a blowout," Pedroia said.
Said Yankees manager Joe Girardi: "It's very unfortunate that he hit him. It's 13-4. We're not trying to hit anyone."
- The Yankees acquired pitcher Chad Gaudin from the San Diego Padres for a player to be named, announcing the deal during the game.
- The Red Sox put OF Rocco Baldelli on the 15-day disabled list because of a bruised left ankle and recalled OF Josh Reddick from Triple-A Pawtucket.
- Yankees pitchers issued 12 walks, their most in a win since 1967 when they walked a dozen in a 4-3 victory over Boston.