With two outs in the second and Iwamura at-bat facing a 2-2 count, Yankees manager Joe Torre stepped from the dugout to talk to home-plate umpire Kerwin Danley, who called in the rest of the crew for a conference.
Rays manager Joe Maddon was then summoned from the dugout. When the meeting was finished, Iwamura had to hand over his bat to the umpiring crew. He then struck out swinging to end the inning.
"I was surprised," Iwamura said. "... Even before I left Japan, I sent my bat to see if it's OK with Major League Baseball."
According to Rays team spokeman Chris Costello, the Yankees questioned the flatness of the end of Iwamura's bat.
"Torre contends that no manufacturer makes a bat sawed off at the end like that, and he wanted to determine whether it was a legal bat or an illegal bat," crew chief Dana DeMuth said. "We respected his request."
Iwamura's bat was sent to the Commissioner's Office for inspection.
In Alex Rodriguez's next at-bat in the third, Maddon approached the umpires to question the Yankees third baseman's bat. Once the talking finished, Rodriguez had to hand over his bat.
"It was just retaliation," said Maddon of his decision to challenge Rodriguez's bat. "There's nothing wrong with Alex Rodriguez. He's a great player. It was tit for tat entirely."
Maddon smiled when asked what he told the umpires while making his challenge.
"I said it's an illegal bat," Maddon said. "There must be something inside it, but there might be something inside that bat. I don't have X-ray vision. He's got 45 home runs on Sept. 1. That was my argument."
Rodriguez didn't miss a beat after his bat was confiscated, driving an RBI single between third and shortstop to keep the Yankees' two-run rally going. The slugger added a ground-rule double down the left-field line in his next at-bat to drive home two more and put the Yankees up, 7-2.
A-Rod's bat was also sent to the Commissioner's Office for inspection.
"It doesn't matter which bat he uses, it's more about his physical abilities," Maddon said. "He could use a broom handle and be successful."
Bill Chastain is a reporter for MLB.com. Associate reporter Anthony DiComo contributed to this story. This story was not subject to the approval of Major League Baseball or its clubs.