* Arsenal struggle to beat Championship side
* Wenger has chance to end nine years without a trophy
* Wigan push Arsenal all the way but fail in the shootout (Adding details, quotes)
By Mike Collett
LONDON, April 12 (Reuters) - Arsenal rode their luck to beat holders Wigan Athletic 4-2 on penalties and reach the FA Cup final for the first time in nine years after their semi-final ended in a 1-1 draw after extra time at Wembley on Saturday.
They struggled for long periods against the Championship side who only wilted in the final minutes of normal time and lost their nerve when it came to the decisive shootout in which Lukasz Fabianski twice made great saves for the Gunners.
Santi Cazorla scored the decisive spot kick to send Arsenal into the final for the 18th time, equalling Manchester United's record, and they can join United on 11 FA Cup triumphs if they beat either Hull City or Sheffield United in the May 17 final.
They meet in the second semi at Wembley on Sunday.
Trailing with 82 minutes on the clock Arsenal's season looked about to reach a new low after a spectacular recent collapse in the Premier League before Per Mertesacker cancelled out Jordi Gomez's 63rd minute penalty.
Arsenal manager Arsene Wenger, looking for the club's first silverware since beating Manchester United in that 2005 Cup final, told reporters: "I am relieved because we won. There was big pressure on us but I expected a very difficult game and I was not disappointed.
"Wigan were well organised and physically very strong. They played very well and showed why they knocked Manchester City out in the quarter-final."
Wigan coach Uwe Rosler told reporters: "I couldn't have asked for more. I am absolutely proud of the performance.
"You need a little bit of luck with the penalties and we didn't have it on our side today."
Wigan, who stunned Manchester City to win the trophy last year only to suffer Premier League relegation, saw their dream of retaining the Cup ended after Gary Caldwell and Jack Collison had their first two penalties saved by Fabianski.
Arsenal held their nerve in the shoot-out with Mikel Arteta Kim Kallstrom, Olivier Giroud and Cazorla all giving former England keeper Scott Carson no chance with their kicks.
After Caldwell and Collison's efforts were saved, Jean Beausejour and James McArthur scored, but it was too late to save Wigan, who are on course to secure a Championship playoff spot and on the form they showed on Saturday, could regain the Premier League place they lost last season.
Wigan, who knocked out Premier League sides Crystal Palace and Cardiff City before shocking Man City again on their way to the last four, took the lead when Mertesacker's lunging tackle on Callum McManaman earned Wigan a penalty.
Gomez needed nerves of steel to convert his penalty as he had to wait for three minutes while Arsenal defender Nacho Monreal received treatment for an injury.
When he finally did step up the Spaniard planted his left-foot shot wide of Fabianski who dived the right way but could not reach it.
That triggered Arsenal's best spell of the match and they began to put Wigan under increasing pressure as the clock ticked down.
Alex Oxlade-Chamberlain was at the heart of most of Arsenal's best moves and it was no real surprise when they equalised with eight minutes of normal time remaining.
Although they had been poor for the entire first half their goal came when they finally injected some pace into their game and followed a series of attacks which saw Bacary Sagna hit the post, Carson save brilliantly from a Kieran Gibbs header and then Stephen Crainey clear off the line.
Mertesacker made up for conceding the penalty by beating the offside trap to glance his header home from close range.
Oxlade-Chamberlain, by far Arsenal's best player almost settled the match in extra time when he thundered a powerful drive against the bar in the 111th minute but Collison could have won it for Wigan with a header close to the end.
The start of the match was delayed until seven minutes past the original kickoff time of 5pm local time (1600GMT) to mark the 25th anniversary of the Hillsborough disaster 25 years ago this weekend.
That game was abandoned six minutes after it started and a minutes silence was added to that time as a mark of respect to the 96 Liverpool fans who lost their lives at the 1989 FA Cup semi between Liverpool and Nottingham Forest in Sheffield.
While the anniversary was marked throughout the senior English leagues, there was a specially poignant reminder at Wembley.
Ninety-six seats were left empty and draped in Liverpool scarves, the players wore black armbands, the names of the victims were displayed on the stadium's electronic scoreboard and wreaths were laid in both technical areas.
Wenger stalked his technical area like a man waiting for a trapdoor to open but he now has the chance to end Arsenal's long wait for a trophy.
But it wasn't all good news for him and his side. Everton's win at Sunderland meant they moved into the top four and a possible Champions League place next season, pushing Arsenal down to fifth place, two points behind having played the same number of games. (Editing by martyn Herman)