Second-tier Wigan stunned Manchester City for the second straight year in the FA Cup, beating the Premier League giants 2-1 to reach the semifinals and stay on course to retain the trophy.
Seven days after winning the League Cup final at Wembley Stadium, City were looking to return to the "Home of Football" for the last four of the FA Cup and avenge last season's surprise defeat to Wigan.
It was a tactical triumph for visiting manager Uwe Rosler, an East German who spent four years at City from 1994-98 and became a cult hero at the club.
City manager Manuel Pellegrini fielded a raft of second-string players with Wednesday's Champions League match against Barcelona in mind and the gamble of starting without the likes of Vincent Kompany, David Silva and Fernandinho backfired.
Gomez converted a 27th-minute penalty after Martin Demichelis fouled Marc-Antoine Fortune and Perch tapped in Wigan's second in the 47th.
"People kept saying we were lucky last year but we're going back to Wembley and we're making history again," Wigan captain Emmerson Boyce said.
Sheffield United through
Wigan's reward is a semifinal against Arsenal, who are now overwhelming favourites to win the competition following a 4-1 win over Everton on Saturday, ending their nine-year trophy drought.
Earlier, Sheffield United became the first third-tier team to reach the semifinals since 2001 by beating Charlton 2-0 and will next play Hull, who defeated Sunderland 3-0.
Hull captain Curtis Davies rose highest in the 68th to head in Tom Huddlestone's free kick, before David Meyler supplied a cool finish four minutes later after chasing down a punt upfield.
Lee Cattermole played a shocking back pass that left the lurking Matty Fryatt with the simplest of chances to score just minutes later.
The semifinals will be played on 12th-13th April.