Columbus and Cincinnati wins set up derby clash in Eastern Conference final
Christian Ramirez and Cucho Hernandez scored extra-time goals as the Crew beat 10-man Orlando City 2-0 after extra time on Saturday.
Then a scrappy encounter between Cincinnati and the Philadelphia Union was decided by a controversial winner late in stoppage time from Yerson Mosquera to give Cincy a 1-0 win and the right to host the conference final.
The Crew had the upper hand for large stretches of the game and went close in the first half when midfielder Aidan Morris saw his shot pushed wide by Orlando keeper Pedro Gallese and then Hernandez blasted just wide after good work from the lively Diego Rossi.
Orlando were defending valiantly and threatened at times on the break, but they found themselves a man down in the 78th minute when Argentine defender Rodrigo Schlegel was sent off for a second yellow card when he bundled down a goal-bound Rossi.
Columbus pushed forward in search of the winner but they almost got caught out at the break when a poor header from Rudy Camacho fell to Facundo Torres who fed Martin Ojeda only for the Argentine to fire his shot wide.
Columbus coach Wilfried Nancy introduced Ramirez for extra-time and within two minutes the moved had paid off handsomely.
Morris won the ball on the edge of the box, burst down the right and fired in a low cross which Ramirez slid into the net from close range.
Orlando responded positively though with Kyle Smith forcing Crew keeper Patrick Schulte into a fine save with his left leg after being put through by a beautiful pass from Junior Urso.
Schulte then did well to keep out an effort from Ramiro Enrique and then delivered a magnificent reaction save to keep out an Enrique header.
But deep in the second period of extra-time, Gallese was caught out when he had pushed up near the half-way line and Hernandez rounded him and fired into the unguarded goal from over 50 yards out.
Ramirez said he was delighted to have got off the bench to make the difference.
"I was just itching to get out on the pitch. I felt that we were just missing some presence in the box. So just told myself, if I get in there, I'm just gonna be inside the box - and got on the end of one," he said.
Cincinnati, the top seed in the MLS playoffs after winning the Supporters' Shield for the best regular season record, started frantically in front of a packed TQL Stadium.
But while playmaker Luciano Acosta was busy and prompting, Philadelphia weathered the storm of early attacks, keeping Cincinnati's strike-threat Brandon Vazquez quiet.
Winger Aaron Boupendza provided the most dangerous moments in the first half and threatened to open the scoring in the 35th minute when he burst forward centrally but his shot from the edge of the box was tipped wide by Andre Blake.
Philadelphia showed more attacking intent after the break with Julian Carranza finding space to move down the right but he fired his shot, from a tight angle, into the side-netting.
Nathan Harriel forced Cincinnati keeper Roman Celentano into a diving save with a first time effort from the edge of the box as the Union looked to break the deadlock.
Mosquera's moment
The game looked to be heading towards extra-time, but four minutes into stoppage time Alvaro Barreal whipped in a ball from deep on the left and Ian Murphy headed down to Colombian Mosquera who buried his shot into the corner.
Television replays suggested that Murphy may have been in an offside position when he set-up Mosquera but the VAR review gave the thumbs-up to the goal.
"We have an Ipad obviously on the bench and every player and coach who saw it said 'Don't worry it's offside'" said Union coach Jim Curtin.
Cincinnati went close to adding a second when Acosta fed Vazquez but the American striker's shot was well dealt with by Blake.
It was a huge moment for defender Mosquera who is on loan at Cincinnati from Premier League club Wolverhampton Wanderers and is expected to return to England after this season.
Pat Noonan's Cincinnati, who entered MLS in 2019 and struggled badly in their first three seasons, had never before reached the conference final.
Sunday's Western Conference semis see Houston host Sporting Kansas City before defending champions Los Angeles FC travel to two-times champions Seattle Sounders.