The Houston Dynamo had a penalty call overturned by video review and settled for a goalless draw against the Portland Timbers on Monday in the opener of their Western Conference semifinal.
Referee Robert Sibiga awarded the Dynamo a penalty in the 30th minute after Larrys Mabiala's sliding tackle of Alberth Elis at the corner of the box, but the call was overturned after a review despite appearing inconclusive.
Dynamo forward Mauro Manotas, whose' pass played in Elis, said the penalty should have stayed as called.
"It's something that we have to get used to because it's going to be seen a lot," Manotas said of the review system, which is new to MLS this season.
"Today, we were the ones who were persecuted because it was a play, that for me, it was a penalty. Because apart from the fact that the defender got the ball, the defender went in forcefully into Alberth and took him out."
Elis, though, said the penalty decision was not the only factor in the result.
"The game stayed the same," he said. "We improved in the second half and we had some more opportunities and now we have to go and get a result that can take us to the [Western Conference] final."
The Timbers also had a penalty shout in the first half when Houston goalkeeper Tyler Deric took out Darren Mattocks, but Sibiga did not give it.
Portland goalkeeper Jeff Attinella posted his 10th career clean sheet in his first playoff game, making two saves early in the second half -- a sliding one-on-one save against Elis and a leaping stop of a Philippe Senderos header.
The second leg is Sunday in Portland, but the Timbers will have to make some changes after midfielders Darlington Nagbe and Diego Chara and defender Mabiala all left the game with injuries.
Chara who was taken off on a stretcher, and Timbers coach Caleb Porter confirmed after the game that he had a broken foot and would not be in contention to return for the second leg.
The top-seeded Timbers were already without Fanendo Adi, Sebastian Blanco and David Guzman. Adi was second on the team with 10 goals despite missing the final 10 regular-season games after he injured a hamstring during a 3-1 win over LA on Aug. 6.
The fourth-seeded Dynamo, unbeaten in their last eight matches, had just one road win in the regular season, but will be able to advance with a scoring draw in Portland after holding firm at home.
Information from The Associated Press was used in this report.