Pena connected on a 1-1 pitch from A.J. Burnett in the first inning, sending a shot over the right-field wall for his 46th home run of the season.
"A.J. has incredible stuff. [His] breaking pitches are devastating, his fastball even more so," Pena said. "Honestly, I was just trying to focus on seeing the ball as well as I could and as early as I could. And I was able to put the bat on the ball."
Pena's final home run completed a most unlikely year that saw him report to Spring Training as a non-roster invitee, actually get told he wasn't on the team before then making the team, winning the starting first-base job and, ultimately, hitting more home runs than any player in Rays history. And by going from one home run in 2006 to 46 in 2007, Pena enjoyed the second-largest one-year increase in Major League history, trailing only Mark McGwire, who went from three in 1986 to 49 in 1987.
"I'm glad we got that win, just to end it up on a good note," Pena said. "I think we played, overall, a pretty good ballgame. And, personally, I'm just extremely happy and thankful and excited about it all. It won't be until probably when I'm at home on the couch that I'm able to look at what happened slowly, the details and all that stuff. One thing's for sure, I'm really grateful."
Rays manager Joe Maddon couldn't say enough nice things about Pena.
"You know what I love, how he took every at-bat," Maddon said. "He does not waste an at-bat. ... I think Carlos, as this season went on, really became involved with his at-bats. Every at-bat became a new adventure. I think as the season wore on, this last month, his pitch selection got even better."
Meanwhile, Iwamura, who played third base all season, started Sunday's game at second. The Rays want Iwamura to learn the position during the offseason in the event top prospect Evan Longoria wins the third-base job during Spring Training.
"Obviously second base is a different position," Iwamura said. "[Playing there compared to playing third] was like a long-distance runner moving to a shorter distance."
Iwamura took ground balls before the game to acclimate himself to the position he hasn't played since playing a few innings there during a USA-Japan All-Star game in 2002. Despite the rust and inexperience at the position, Iwamura looked smooth turning an inning-ending double play in the second.
"He really turned that double play well," Maddon said. "It was a great feed by [Joel Guzman], but I liked the way he hung in there and the velocity on his throw to first base. He played there really well. That was nice to see. ... He's got a really good game awareness at second base."
The Rays jumped on Burnett for five runs in the sixth, pounding out five hits. Greg Norton, Raul Casanova, Jonny Gomes, Joel Guzman and Justin Ruggiano each had an RBI in the inning.
Jason Hammel started for the Rays on the last day of the season, as he did in 2006, and the right-hander held the Jays to four runs on five hits while walking two and striking out six in five innings. Unlike in 2006, when Hammel took the loss in Cleveland, he picked up his third win of the season Sunday.
"I got one win and one loss on the finish of the year, so it feels real good this time," Hammel said.
Being backed by the Tampa Bay offense is a comforting feeling for Rays pitchers, according to Hammel.
"Keep the team in the game, and this team will score a lot of runs," Hammel said. "It gives you a ton of confidence. It's going to take a lot more than four runs to beat us. They have been scoring a lot of runs all year."
Maddon cited the team's record as the biggest negative from the season, but Sunday's final chapter sat well.
"It was a good way to end the season," Maddon said.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.