The Columbus Crew came back from two goals down to beat top-seeded FC Cincinnati 3-2 after extra-time in a thrilling Major League Soccer Eastern Conference final, booking a place with defending champions Los Angeles FC in the MLS Cup final.

LAFC beat Houston Dynamo 2-0 thanks to a first-half Ryan Hollingshead goal and an 80th minute own goal from Houston Dynamo defender Franco Escobar.

Home side Cincinnati scored twice in the first half of the Ohio derby, with goals from Brandon Vazquez and Luciano Acosta and they held that lead until 15 minutes from the end of regulation.

But an own goal from Alvas Powell and then a Diego Rossi goal in the 86th minute, forced the game into extra-time and Columbus utterly dominated from then on.

The decisive goal came five minutes from the end of extra-time when substitute Christian Ramirez slotted in from close-range.

It was an enthralling encounter from start to finish with Eastern Conference champions and regular season table toppers Cincinnati striking first.

Aaron Boupendza whipped in a cross from the left which US international Vazquez collected before swivelling and burying the ball in the far corner.

Cincinnati had finished rock bottom of the league in their first three seasons in MLS but after tasting the playoffs last year, they have been transformed this season.

They doubled their advantage on the stroke of half-time when, from an indirect free-kick, the league's Most Valuable Player, Argentine Acosta fired in off the inside of the post.

Columbus had played the better football and enjoyed the bulk of possession but trailed 2-0 at the break but French coach Wilfried Nancy resisted the temptation to make changes at the interval.

Boupendza almost killed off the Crew when he found space inside the box but his shot, heading to the far corner, was superbly saved by Crew keeper Patrick Schulte.

But the introduction by Nancy of German wing-back Julian Gressel and striker Ramirez from the bench in the 65th minute, proved to be inspired.

It was Gressel's cross from the right, with Ramirez lurking at the back post, that flew in off the unfortunate Powell to give Columbus a lifeline.

Uruguayan Diego Rossi, who had been superb throughout the game with his clever movement, headed over from a promising position in the 80th minute.

Five minutes later though, the Crew got their reward, when after a clever exchange inside the box by Ramirez and Cucho Hernandez, Rossi poked in the equalizer.

With Columbus having dominated the ball for long stretches, they were the team that had the energy in extra-time with Cincinnati looking spent.

But it was not until five minutes from the very end when Columbus got the winner, Kevin Molino floating a cross to the back post which Hernandez headed across to Ramirez to tap in.

Ramirez had got the late winner in the previous round of the playoffs against Orlando and the 32-year-old Californian was hailed as the hero again at the final whistle.

"The goal was to win MLS Cup and I think we were close, and that's why it hurts," Cincinnati coach Pat Noonan told reporters.

"It hurts because of losing at home, it hurts because of the scoreline mid-game, it hurts because of who beat us. So there's a lot of things that make this a hard one to take and I feel for the guys," he added.

Columbus will be looking for their third MLS Cup title after triumphs in 2008 and 2020 when they take on an LAFC team that enjoyed a relatively comfortable win against US Open Cup winners Houston.

The home side started strongly with their Mexican forward Carlos Vela hitting the bar in the opening minute, scooping the ball over Houston keeper Steve Clark but being denied by the woodwork.

The 34-year-old Vela, whose contract with LAFC runs out at the end of this season, had the ball in the net three minutes later but his effort was flagged for offside.

Houston fired a warning shot when their Mexican talisman Hector Herrera crossed from the left and Corey Baird's volley was denied only by a fine save from Max Crepeau.

LAFC got in front when veteran Italian defender Giorgio Chiellini's header from a corner was parried out by Steve Clark only for Hollingshead to pounce and drive home the loose ball.

LAFC made sure of their return to the final when, in the 80th minute, Denis Bouanga fed Diego Palacios down the left and his low ball was turned into his own net by the sliding Escobar.