Los Angeles fell to Real Salt Lake on penalties in the final two season ago, so the Galaxy will enter the match with a chip on their shoulders.
The Galaxy defeated Red Bull New York 2-1 on Thursday, 3-1 on aggregate, to move to within one win of the 2011 MLS Cup Final.
Mike Magee scored twice over the two-legged affair while Landon Donovan converted a penalty in the second match to wrap up the scoring, but it was an inspirational performance from David Beckham on Thursday that helped the Galaxy prevail.
Beckham's chronic back injuries were put to the test in the first half following an awkward collision with Dane Richards, but it did not prevent the Designated Player from carrying the Galaxy on his back for the remainder of the game.
"He's a player with an unbelievable desire to win and compete," head coach Bruce Arena said of Beckham after the second-leg win. "When we got down a goal, David helped pick up the team. His energy in the second half and earning the penalty it was all David. David, I think, was an inspiration to our team."
Real Salt Lake was lifted by a strong performance as well, as defender Robbie Russell was propped up by head coach Jason Kreis after a 3-2 aggregate win over Seattle Sounders FC.
"He's been absolutely spectacular in the last two matches," Kreis told MLSsoccer.com after his return to Salt Lake. "[He's] probably the best defender of all of them in the two matches.
"He's consistent in making plays, and making tackles when it counts. That's what you need is guys with experience who step forward in those critical situations."
The Claret-and-Cobalt experienced a disappointing close to the MLS regular season, only managing a record of 0-4-2 over its final six games down the stretch.
But Real Salt Lake came out guns blazing in the postseason, opening with a 3-0 home win over the Sounders.
With first-choice defenders Jamison Olave and Nat Borchers both sustaining injuries in the win, Kreis resorted to a makeshift back line in the return match on Wednesday, starting Chris Wingert and Chris Schuler instead. The match ended 2-0 in favor of Seattle.
"It wasn't perfect, certainly," Kreis said of the performance put forth by his center-backs. "To be fair, it was a night that our center-backs were going to be very busy. With the amount of balls that were served into their forwards, they forced a lot of mistakes.
"But we need to take the next couple of days and really review the video critically with those two players because if they're going to be in there again, we're going to need improved performance."
It is the third time in four years that Real Salt Lake has advanced to an MLS Conference Final, losing to New York 1-0 in the 2008 edition but defeating the Chicago Fire 5-4 on penalties a year later.
Los Angeles enters Sunday's clash with one fewer day's rest than its opponent, simulating a common occurrence for the Galaxy this year of having a midweek fixture surrounded by a pair of weekend matches.
"This is maybe the tenth time this year we've done this," Arena said. "We know how to recover for this. It's never easy but we'll get our team recovered. Obviously, the players that played [Thursday] will have a real easy couple of days to get ready for Sunday."