FC Cincinnati booked their place in the semi-finals of the MLS Cup Eastern Conference playoffs on Saturday after defeating New York Red Bulls on penalties to complete a 2-0 first-round series victory.

An absorbing contest at the Red Bull Arena was decided on spot-kicks after top seeds Cincinnati came from behind to snatch a 1-1 draw and send the match straight to a shootout.

Cincinnati's Argentine goalkeeper, Roman Celentano, was the hero for the visitors, diving to save New York's 10th penalty from Andres Reyes to seal an 8-7 victory.

The defeat was cruel on eighth-seeded New York, which saw midfielder John Tolkin and teenage substitute Serge Ngoma both miss penalties that would have secured a victory and forced a decider in the best-of-three series.

The result sends Cincinnati into a semi-final against either Philadelphia Union or New England Revolution.

Cincinnati had almost won the game in 90 minutes when a corner from captain Luciano Acosta deep into stoppage time was bundled into the net with what appeared to be the final kick of the match.

Cincinnati's players celebrated but the goal was chalked off after VAR ruled that New York goalkeeper Carlos Coronel had been impeded in the six-yard box.

Earlier, New York had taken the lead in first half added time after Tom Barlow prodded home from close range.

That goal itself was tinged with controversy, with Barlow fortunate to be on the field after escaping a red card for a wild tackle on Yerson Mosquera moments earlier.

Cincinnati, which finished 26 points ahead of New York in the regular season standings, launched a furious second-half onslaught as New York battled to hold onto the lead.

Eventually the Cincinnati pressure told, with Acosta surging forward from midfield on the counter attack before slipping a pass to Aaron Boupendza, whose low-angled shot across goal beat the diving Coronel to make it 1-1.

In the Western Conference playoffs meanwhile, seventh seed FC Dallas scored a series-leveling 3-1 victory over the second-seeded Seattle Sounders to set up a winner-take-all game three next Friday.

US international team-mates Paul Arriola and Jesus Ferreira fired Dallas into a 2-0 lead after just 18 minutes at Toyota Stadium in Frisco to set the Texas club on their way to victory.

Seattle responded with an individual effort from Jordan Morris on 48 minutes and pressed hard for an equaliser, but Dallas made the game safe with an 89th-minute goal from Colombian forward Jader Obrian.