After Lodeiro scored from the penalty spot in the 83rd minute, Bruin tied it in at the end of stoppage time for Seattle, which avoided a second straight defeat to start the season.
Matteo Mancosu opened the scoring in the 17th minute. Patrice Bernier got the ball to Ignacio Piatti, who found Mancosu on a run behind the defense. The Italian made a move to the left and slotted the ball into an open goal.
Montreal struck again in the 51st minute when Piatti was able to charge in and score from a low shot.
With seven minutes to play, the crowd booed as referee Jair Marrufo pointed to the spot when substitute Oniel Fisher went down easily after a brush with Laurent Ciman just inside the 18-yard box. Lodeiro made no mistake with a low shot.
The Sounders thought they had a late equalizer after a give-and-go between Jordan Morris and Clint Dempsey, only for it to be nullified by a handball in the buildup. But moments later, Cristian Roldan's cross from the right side was headed down by Morris, and Bruin slammed it in.
Tim Howard returned to the Colorado Rapids lineup but was undone by an own goal as the New York Red Bulls earned a 1-0 win.
The U.S. goalkeeper was injured on international duty in November and missed the Rapids' season opener after spending the entire offseason recovering from surgery.
Howard was called into action in the 23rd minute when Bradley-Wright Phillips got in behind the Rapids' back line, but the 38-year-old made the save.
But the Red Bulls took the lead a minute before halftime as Eric Miller turned in a low cross while trying to stay in front of Daniel Royer.
New York goalkeeper Luis Robles set an MLS record by playing in his 142nd consecutive game as the Red Bulls won their second straight to open the season.
The Chicago Fire beat Real Salt Lake 2-0 after Nemanja Nikolic and Arturo Alvarez each scored in the opening 15 minutes.
Nikolic started the scoring in the 11th minute. He was in an offside position but the ball fell to him asRSL's Sunny took the ball away from Michael de Leeuw, and the forward beat goalkeeper Nick Rimando one-on-one.
Alvarez scored four minutes later. He dribbled in space on the right side, cut inside with three touches along the 18-yard box and rolled in a deflected shot off defender David Horst.
Rimando kept RSL in it. He barely got a hand on Nikolic's open shot in the 50th minute and in the 81st, Rimando dove to his left to punch away Juninho's free kick from just outside the area.
The Fire earned their first win after both clubs opened the season with draws last weekend.
Toronto FC earned a 2-2 draw at the Philadelphia Union but lost star player Sebastian Giovinco to a leg injury.
The Union took the lead on 10 minutes when Chris Pontius headed down for Jay Simpson to nod into the net.
Philadelphia had a chance to double their lead when Nick Hagglund hauled down Fabian Herbers at the edge of the area, but Alejandro Bedoya hit the bar with the resulting penalty.
Giovinco picked up a leg contusion just before halftime, but even before he could be helped down the tunnel, Jozy Altidore drew a penalty and and then converted it to even the score.
Justin Morrow then put Toronto ahead in the 71st minute after a quick restart, but C.J. Sapong beat the offside trap to hit back two minutes later for the Union.
Romell Quioto scored 67 seconds into the match and the Houston Dynamo went on to cruise pastColumbus Crew SC 3-1.
Will Trapp passed back to Columbus goalkeeper Zack Steffen, who attempted a slow, rolling pass back to the midfielder. Quioto intercepted the ball just outside the penalty area, took several touches and beat Steffen between the legs with a right-footed shot from about 14 yards.
Alberth Elis scored following Alex's corner kick the 35th minute, his first MLS goal, and Erick Torres made it 3-0 in the 65th for the Dynamo, with Alex again assisting. Quioto and Torres also scored in the Dynamo's 2-1 opening win against defending champion Seattle.
Columbus' Jonathan Mensah was issued a red card for violent conduct in the 87th minute, before Ola Kamara scored a consolation goal in the third minute of stoppage time.
A new-look FC Dallas side held Sporting Kansas City to a goalless draw.
With a CONCACAF Champions League clash ahead on Wednesday, Dallas made seven changes from their season opening win at the LA Galaxy.
The visitors allowed Kansas City to maintain the majority of possession but held firm to earn a point.
The New England Revolution's home opener against Orlando City was postponed with the wind chill expected to push temperatures into the single digits.
Sounders need to refine their attack
Herculez Gomez highlights the positives of Montreal's potent attack, as well as the Sounder's grit to grind out results.
Tim Howard looks sharp in return
Sebastian Salazar and Herculez Gomez recap the return of Tim Howard in Colorado's 1-0 loss to the New York Red Bulls.
How good can Chicago be this season?
Herculez Gomez shares his impressions of Chicago's 2-0 win over Real Salt Lake.