The duo entered Sunday's 10-8 win over the Royals tied for the team lead with 16 home runs each. Plouffe regained the lead in the second inning, only for Willingham to tie it up again with a three-run shot in the sixth inning.
Not to be outdone, Plouffe hit another solo shot two batters later, this time putting the Twins up 6-5 and capping a five-run sixth inning.
Sunday marked the sixth time this season that Plouffe and Willingham have homered on the same day. That includes Saturday, when Plouffe hit one in the first game of Minnesota's double-header against Kansas City and Willingham hit one in the second.
"It's been kind of ironic that we have hit several home runs on the same day," Willingham said. "Hopefully it continues."
While it appears as if Willingham and Plouffe fuel each other when one or the other homers, Plouffe called the occurrences merely a coincidence.
"I've definitely learned a lot from him this year, just about what kind of hitter I want to be, just staying within myself, not trying to do things that I can't do," Plouffe said of Willingham. "It's worked out. We've both put some balls in the seats lately and that's helped our team."
Added catcher Joe Mauer: "It's kind of fun to watch those guys go back and forth a little bit."
All three of the homers hit by Plouffe and Willingham on Sunday came off Royals starter Bruce Chen, who has had the Twins' number in recent years. Both of Plouffe's home run swings were on the first pitch from Chen.
Oddly enough, 16 of Plouffe's 18 home runs have been solo homers. The other two were two-run shots. Still, the 26-year-old Plouffe has carried his June tear into the month of July.
"When he's swinging the bat well and getting pitches to hit, he's squaring them up to left field," Willingham said. "When he hits the ball in the air and puts the barrel on it, he hits them out of the ballpark."
Willingham's big three-run homer came just hours after it was announced that he did not make this year's All-Star team despite being perhaps Minnesota's most productive and most consistent hitter through the first half of the season. Instead, Mauer was chosen as the Twins' lone 2012 All-Star.
Willingham isn't one to talk much about missing out on an All-Star nod, however. He let his bat do the talking instead.
"The only thing I can say is that I'm happy with the way my season's gone so far," Willingham said. "Obviously we want to keep winning as a team. I'm happy for Joe. He deserves to go. He's going to represent this team well."
Twins manager Ron Gardenhire was asked earlier this weekend who he thought his team's All-Stars should be. Willingham's name certainly was high on the skipper's list.
"Willy has been doing that for us all year. I think that's the disappointment in him not being an All Star," Gardenhire said after Sunday's win. "He's been there from Day 1. He's been carrying the load for our baseball team an awful lot. I sure was hoping that he would get a chance to play in an All-Star game. He's very deserving of it, and he just added onto his numbers today."
Mauer's numbers have been impressive this season -- a league-leading on-base percentage of .416 prior to Sunday while batting .324 -- and he made the All-Star roster at a less crowded position, whereas Willingham was facing a logjam at outfield.
Still, Willingham's first half of the season was enough for him to get strong All-Star consideration -- and high praise from his teammates.
"He's been doing that all year for us," Mauer said of Willingham's homer. "We get some guys on and he's got a big bat. He came through again."
Willingham and Plouffe are putting on somewhat of their own home run race, with each trying to outdo the other as they fight to reclaim the team lead. Off the field, though, it's clear that both players aren't as wrapped up in their individual feats as they are in helping the 33-45 Twins dig out of a hole.
"I want to win. I want to be part of the team," Plouffe said. "I want to play. Right now we're coming off a good series here and taking it to Detroit."