Justin Morneau hit two home runs and had a career-high six RBI as the Twins knocked out Millwood in the second inning of a 15-5 rout.
"I can't tell you how many guys had a good night because I lost track," Twins manager Ron Gardenhire said. "We've been on the other side of that recently so we know how that feels."
The Twins, who began the night tied for next-to-last in the AL with 131 runs, had 15 baserunners in the first three innings.
Minnesota went on set a season-high for runs and had a season-best 19 hits.
"We got some pitches to hit," Morneau said. "Sometimes you just run into a lineup where everybody's hitting."
The Twins' offense has been better lately, averaging 7.2 runs over the past five games.
Hunter is 16-for-34 (.471) in eight games in May.
Millwood, who signed a five-year, $60 million free agent contract in the offseason, was roughed up for nine runs and nine hits in 1 1/3 innings. It was his shortest start since 2000, when he lasted one-third of an inning for Atlanta against Pittsburgh.
Millwood (3-3) matched the most runs allowed in his career, also having yielded nine to Toronto on June 7, 2000, while pitching for the Braves.
"It was just a bad day," Millwood said. "What can you say? I can't remember an outing quite like this. It definitely wasn't what I expected going out there."
Millwood fell to 0-3 in six career starts against the Twins.
"He's had trouble against them in the past," Rangers manager Buck Showalter said. "He got a lot of pitches over the middle of the plate and he paid for it. They were aggressive and it worked out for them. Over the course of the season, Kevin will give us a chance to win most nights."
Provided with a nine-run cushion after two innings, Minnesota starter Carlos Silva (2-5) cruised to his first victory since April 12. Silva allowed five runs and 11 hits in six innings.
Silva said he never felt comfortable even with a big early lead.
"It's not easy to relax when you're facing those kinds of hitters," Silva said.
Five of the first six hitters reached base against Millwood, who pitched a complete-game 8-2 victory over Baltimore in his previous start.
Hunter got the scoring started with an RBI single and Cuddyer followed with a run-scoring double. Morneau's three-run blast into the Texas bullpen in right-center made it 5-0.
"I was just trying to use the big part of the field," Morneau said. "Especially in right-center the ball carries well here."
Hunter's RBI single in the second stretched Minnesota's lead to 7-0. Two hitters later, Millwood was out of the game.
Blalock and Mench homered in the fourth to make it 10-2, and Young's RBI single in the fifth got the Rangers within seven runs. In the sixth, Rod Barajas' run-scoring double and Gary Matthews Jr.'s RBI groundout made it 10-5.
The Twins added one run in the seventh and two in the eighth, then Morneau capped the scoring with his eighth homer, a two-run shot in the ninth.
"Six RBI, that's a good day," Morneau said.
Francisco Liriano pitched three innings for his first career save. ... It was Morneau's third career multihomer game. ... Cuddyer extended his hitting streak to 10 games. ... Millwood's shortest outing for Cleveland last season was three innings. He had lasted at least five innings in each of his first seven starts for Texas. ... Young hit his team-high 16th double for Texas. ... The Rangers had gone four games without a homer until Blalock's blast. ... Matthews extended his hitting streak to 11 games. ... Rangers third base coach Steve Smith returned after serving a five-game suspension for an altercation with an umpire.