Los Angeles FC and Philadelphia Union will battle for the MLS Cup on Saturday in a rare collision of the top seeds in Major League Soccer's championship showpiece.

Los Angeles, who finished top of the Western Conference regular season standings, will host the final at their gleaming Banc of California Stadium home just four years after joining the league.

Philadelphia, who topped the Eastern Conference in the regular season, sealed their place in the final last weekend after a battling 3-1 win over old rivals New York City FC at home.

It is the first time since the 2003 season that the two teams with the best regular season records have advanced to the MLS Cup final.

For Los Angeles, Saturday's final offers the chance to crown a meteoric rise to the top of club football in the United States and Canada.

The club suffered agonising playoff exits in 2018, 2019 and 2020, before missing the postseason altogether in 2021.

But under new coach Steve Cherundolo, Los Angeles were reborn this season, finishing top of the Western Conference 11 points clear of Austin.

They then took care of Los Angeles Galaxy in the Western Conference playoff semi-finals before downing Austin 3-0 on Sunday to reach the MLS Cup.

"This is for the fans and it's also for everybody at the organization who has worked so hard in the past seven years to put this club and organization on the map, to build it the right way, and for the right reasons: to win for the city and the fans," Cherundolo said after Sunday's win over Austin.

"The next game is for LA and our fans."

Ironically, Los Angeles have reached the championship game largely without the services of their high-profile signing, Wales captain Gareth Bale.

Bale was signed in July for the purpose of boosting LAFC's championship push.

But the 33-year-old former Real Madrid star has not played at all during the playoffs, with his last outing a five-minute appearance as a substitute on October 2. Bale could make the bench for Saturday's final but is highly unlikely to start.

Philadelphia meanwhile are determined to atone for last season, when they were eliminated in the conference semi-finals by New York.

"We've got a bitter taste in our mouths from last year, the way it ended," the Union's former US international Alejandro Bedoya said. "We were so close to achieving our goals."

Philadelphia coach Jim Curtin is also under no illusions about the challenge presented by Los Angeles' fiercely partisan home fans, who have made the Banc of California Stadium one of the most intimidating arenas in MLS.

"It is rare that the two best teams get to a final," Curtin said. "I think you also have the two best fan bases. LAFC's fans are no joke. It's an intimidating place. It's not soccer moms and dads. It's a real tough place to go."

Nevertheless Curtin says his team have the sort of scrappy, dogged mentality that can cause problems for Los Angeles.

"We have players who are willing to grind and fight," Curtin said this week.

"We're not fun to play against. You can call it what you want: attractive, entertaining, you can hate it, you can call it too physical, whatever you want, we don't really care.

"The players have a lot of big pressure games under their belt -- a lot of playoff wins now and a feeling we can beat any team."