Mauer, who also flied out twice, is batting .250 through five spring games after making the full-time switch to first base.
The Phillies fell to 2-8-1 this spring, among the worst records in the majors.
A two-base throwing error by Twins third baseman Brandon Waring opened the door for the Phillies to tie the game in the eighth inning against Twins right-hander Kyle Gibson.
Right-hander Sam Deduno, who is battling Gibson and several others for the final rotation sport, threw three innings of shutout relief.
Phillies: Ex-Twins right-hander Jeff Manship gave up a first-inning run on Mauer's RBI single but still managed to turn in three solid innings. In seven innings this spring, Manship has allowed just one run.
"Today was a good test, coming in here to pitch against my old team and keeping my emotions in check," Manship said. "I was happy with how things went."
Twins: Right-hander Mike Pelfrey allowed two walks but no hits in three shutout innings, marking his longest outing of the spring. Pelfrey fell behind 1-0 to half of the 10 batters he faced, but a double play and a caught stealing helped his cause.
"I felt good when I walked off," said Pelfrey, now more than 22 months removed from Tommy John surgery. "That's the biggest thing in spring training. You want to feel good when you walk off, and I did that."
Phillies: Left-hander Cole Hamels remains out with tendinitis in his throwing shoulder.
Twins: Shortstop Pedro Florimon could get into spring games by the end of the week as he continues his recovery from a Feb. 17 appendectomy. . Outfielders Aaron Hicks (throwing elbow) and Oswaldo Arcia (illness) could return to the lineup Tuesday. They last played on Wednesday.
BUXTON SENT OUT
Outfielder Byron Buxton, the consensus top prospect in the minor leagues, headed the list of 16 Twins players optioned or reassigned to minor league camp.
Buxton, 20, went 3 for 22 (.136) in his first big-league spring training, including a B game on Friday at Bradenton. He figures to open the season at Double-A New Britain.
Right-handers Alex Meyer and Trevor May, second baseman Jorge Polanco and outfielder Max Kepler were other top Twins prospects sent back to minor-league camp. In addition, third baseman Miguel Sano was reassigned before undergoing Tommy John surgery on Wednesday in New York.
Instant replay was used to review two plays in a span of three pitches in the top of the eighth inning. Both calls were upheld.
The first review involved whether an errant throw from Twins third baseman Waring carried out of play behind first base. Moments later, crew chief Bob Davidson reviewed whether his safe call on John Mayberry Jr.'s slide into home was correct.
Twins video coordinator Sean Harlin told manager Ron Gardenhire he was "99 percent sure" Mayberry was out. However, the lack of a suitable camera angle prevented the call from being overturned.
The second review took 2 minutes, 20 seconds.