Iwamura homered in the eighth inning and Tampa Bay beat the Boston Red Sox 2-1 on Saturday night for the Rays' first five-game winning streak in more than two years.
"To play the Sox this well two nights in a row and come out on top, I mean, we've done it in the past and come out on the bottom," Rays manager Joe Maddon said. "I always talk about finishing things off, the last two nights we've been able to finish things off."
Iwamura's two-out, two-run homer, his first since Sept. 3, came on a 1-1 pitch from Buchholz (1-2), who took a one-hit shutout into the inning.
"His stuff was electric," Boston manager Terry Francona said. "He left one breaking ball over the plate."
Iwamura said he looking for a curveball.
"In my second at-bat, he threw me a change-up and I hit it pretty good to center field," Iwamura said through a translator. "In my first three at-bats, I had bad timing on the curveball and I thought he'd throw me a curveball."
Dioner Navarro got the Rays' second hit, a pinch-hit single with one out in the eighth. After Jason Bartlett flew out, Iwamura's shot helped Tampa Bay win its fifth straight for the first time since Aug. 16-21, 2005.
Buchholz allowed two runs and three hits over eight innings in his first complete game of the season. He matched his career-high by striking out nine, and walked two.
"I felt in control," Buchholz said. "I felt like I was getting stronger as the game went on. I throw a pitchers's pitch and he [Iwamura] hit it."
Boston has lost four in a row.
Scott Dohmann (2-0) struck out Manny Ramirez, the only batter he faced in the eighth, to win for the second straight day. He got the victory Friday when he got David Ortiz to hit into an inning-ending double play in the 11th inning.
Troy Percival pitched the ninth for his fifth save in five chances.
Jackson gave up one run and five hits in seven innings. He had four strikeouts and three walks.
Boston's Ortiz was scratched from the starting lineup due to a bruised right knee. He was hurt diving into first base attempting to beat out a double-play grounder in the final inning of Boston's 5-4, 11-inning loss to the Rays on Friday night.
Kevin Youkilis of the Red Sox established a new major league record for first basemen when he fielded his 1,701 consecutive chance without an error in the seventh, recording the out on Eric Hinske's grounder to second. The old mark of 1,700 was set by Stuffy McInnis from May 31, 1921 to June 2, 1922. Youkilis' last error at first came on July 4, 2006, a span of a major league-best 205 games.
"It's not a big deal," Youkilis said. "Winning ballgames is my biggest concern."
Red Sox DH J.D. Drew had an unique two-out infield single in the first. He broke his bat, with the barrel forcing first baseman Carlos Pena to take several steps toward second to avoid it. By the time Pena reached first, Drew was able to beat second baseman Iwamura's throw to the base.
Boston C Jason Varitek (flulike symptoms) was in the starting lineup. He played for the first time since last Saturday when he entered Friday's game in the ninth inning. ... Maddon said LHP Scott Kazmir (left elbow) will "probably" made his first start of the season next Sunday at Boston. ... Boston 3B Mike Lowell (sprained left thumb) went 1-for-4 in his second rehab game with Triple-A Pawtucket. He could rejoin the team Tuesday. ... The Red Sox placed 1B Sean Casey (right hip) on the 15-day disabled list and recalled 1B-OF Brandon Moss from Pawtucket. ... Tampa Bay RHP Al Reyes (right shoulder) struck out two in a scoreless inning for Class-A Vero Beach. He could return Thursday. ... Boston released RHP Dan Kolb from his contract with Pawtucket to make room for RHP Devern Hansack, who returned from a bruised right forearm. ... After the game, the Rays purchased the contract of INF Andy Cannizaro from Triple-A Durham. INF Elliot Johnson was optioned to Durham.