He joined the party on Saturday night.
"You see these other guys throwing up zeros," Bonser said of strong showings by fellow starters Johan Santana, Francisco Liriano and Brad Radke. "I thought, 'Now it's my turn. I need to do the same thing.'"
Bonser (2-1) mixed his breaking ball and offspeed pitches with his fastball much more effectively this time to outshine Prior, scattering six hits and striking out one with no walks. Bonser left to a standing ovation in the seventh, and rookie Jason Kubel had two hits and an RBI for the surging Twins, who won for the 13th time in 15 games.
"Boof threw the ball great," manager Ron Gardenhire said. "He did a super job."
Joe Nathan pitched the ninth for his 12th save in 13 attempts. It was his 100th career save -- 99th as a Twin.
Prior (0-2) looked sharp early in his second game this season after missing the first 2½ months with shoulder problems, but he faded in his final 1 2/3 innings and got little help from his offense.
Phil Nevin had three hits for the Cubs, who only managed to get one runner past second base all night while being baffled by Bonser. Chicago was shut out for the eighth time this season, which leads the majors.
"I felt more comfortable out there," Prior said. "I just didn't put guys away in certain situations. Overall, it was better than my first start."
Prior had a nightmarish first inning in his return to the mound on June 18 against Detroit, allowing six runs and three homers. He lasted just 3 2/3 innings and carried a 17.18 ERA into this start.
He got out of the first inning just fine, with Joe Mauer's warning track flyout to left ending a 1-2-3 frame and looked like his old dominating self through the first four.
Prior struck out three and retired the first nine batters he faced, much to the delight of thousands of Cubs fans in attendance.
"He pitched well," said Twins cleanup hitter Michael Cuddyer, who went 0-for-4. "He spotted his fastball when he had to. As the game went on, he started to get more life to it."
Luis Castillo got the first Twins hit to lead off the fourth inning, and the Twins finally got on the board in the fifth.
Terry Tiffee singled home Torii Hunter and Jason Bartlett followed by turning a 96 mph fastball into an RBI double to the right-center field gap for a 2-0 lead. The hit extended Bartlett's hitting streak to a career-high 10 games and the shortstop has a hit in every game since being called up on June 13.
Prior appeared to be finished after giving up back-to-back two-out singles to Justin Morneau and Hunter in the sixth. The Metrodome speakers blared Hit the road, Jack! as manager Dusty Baker strode to the mound, but the right-hander stayed in the game.
Kubel followed with an RBI single for a 3-0 lead, and that was it for Prior. He gave up three runs on eight hits in 5 2/3 innings and lowered his ERA to 9.68.
"He threw well. His velocity was up. His location was pretty sharp. I'm satisfied with what he did tonight," said Baker, making sure to separate Prior from the rest of the team.
"It's real tiresome looking up and seeing a bunch of zeros up there."
Prior's matchup against Mauer was the first meeting between the top two picks of the 2001 draft. The Twins received some criticism for taking Mauer, a high school catcher from nearby Cretin-Derham Hall in St. Paul, over Prior, the dominating pitcher from Southern Cal.
Five years later, nobody has any complaints. Prior made it to the big leagues in less than a year and won 18 games in 2003, but has struggled with shoulder problems the last two years.
Mauer is leading the majors in hitting in just his second full season and went 1-for-3 with a single against Prior.
- Cubs 2B Tony Womack left the game in the third inning with lower back spasms. He's listed as day to day.
- Nevin led off the second with a single, but was picked off first on a nifty move by Bonser.
- All the Cubs fans helped boost attendance to 42,304, the second-largest Metrodome crowd of the season.