Each team hit a dramatic homer when it was down to its last out in a wild game that featured nine home runs and 29 hits.
Pinch-hitter Jim Thome cracked a two-run homer in the ninth off Phillies reliever Jose Contreras. Two outs later, Mauer's two-run drive off Lidge tied it at 9.
Drew Butera's first career home run, also a pinch-hit shot, gave the Twins a 10-9 lead in the 10th, but pinch-hitter Ross Gload hit a tying homer off closer Jon Rauch (2-1) with two outs in the bottom half.
Mauer's one-out walk against Danys Baez (2-3) got the Twins started in the 11th. Justin Morneau was intentionally walked with a 2-0 count and Rauch advanced the runners with a sacrifice. Young singled to deep shortstop to put the Twins ahead 11-10. Matt Tolbert followed with a two-run triple.
The AL Central-leading Twins snapped a two-game skid. The Phillies had won three straight after going 6-15 and falling into third place in the NL East.
Butera was batting .154 (6 for 39) before he led off the 10th with a homer against Chad Durbin. But Gload ripped a 3-1 pitch just over the right-field wall to tie it. It was his third pinch-hit homer this season.
Trailing 9-4 in the ninth, the Twins came back against Contreras and Lidge. Thome's drive earned the former Phillie a standing ovation and gave him 570 career home runs, breaking a tie with Rafael Palmeiro for 11th place on the career list.
Thome has now homered against each of the 30 major league teams.
After a walk, Lidge came in. He gave up an RBI single to Denard Span before striking out Orlando Hudson for the second out.
But Mauer, the reigning AL MVP, connected for his third homer of the season to tie it at 9. Mauer had 28 home runs last year.
Lidge had been 4 for 4 in save chances. He had a major league-high 11 blown saves last year after his perfect season in 2008 helped the Phillies win the World Series.
Ryan Howard, Wilson Valdez, Raul Ibanez and Jayson Werth also went deep for Philadelphia.
Phillies starter Cole Hamels allowed four runs - three earned - and five hits, striking out seven. The lanky lefty settled in nicely after a shaky first and retired 13 straight before Morneau led off the sixth with a homer.
The Phillies roughed up Kevin Slowey. He allowed seven runs and seven hits in 1 2-3 innings - his shortest career outing.
An offense that slumped badly during a 6-15 stretch has scored 32 runs in the last four games. The Phillies averaged 2.4 runs during their previous 21 games.
Valdez drove a 1-2 pitch just inside the left-field foul pole to give the Phillies a 4-3 lead in the second. It was his second career homer in 189 games. His other one came against Kansas City on Sept. 26, 2004, with the Chicago White Sox.
Hamels followed with an infield single and Placido Polanco hit a one-out double. Chase Utley's sacrifice fly made it 5-3. Howard then hit a towering shot into the seats in right-center for a 7-3 lead, ending Slowey's day. Howard has four homers in the last four games.
Ibanez connected off Jeff Manship in the third to make it 8-3. Ibanez has five homers and 30 RBIs. At this point last year, he had 22 homers and 59 RBIs.
Werth hit an opposite-field shot off Brian Duensing in the seventh.
NOTES: Phillies C Carlos Ruiz needed more tests after getting hit in the head with a broken bat in the eighth inning on Friday night. Ruiz doesn't have a concussion, the team said. ... A crowd of 45,254 was the 73rd straight sellout at Citizens Bank Park.
