"We're lucky we didn't lose 6-0," Seattle coach Sigi Schmid said.
Now, third-seeded RSL will carry its three-goal cushion in the Western Conference semifinal home-and-away aggregate goals series into the second leg Wednesday at CenturyLink Field. The game is scheduled for 8 p.m. MDT.
In the event Seattle wins 3-0 at home, the two teams would play a 30-minute overtime, followed, if needed, by penalty kicks. One road goal by RSL should be more than enough to win the series.
"Seattle is a tough place to play," RSL goalkeeper Nick Rimando said. "You can't be too comfortable with any score. They're still a great team and they'll be better at home, so we have to make sure we do everything right with our bodies, and I'm sure [RSL coach Jason Kreis] will have a game plan for us. … We need to continue to play well."
Real, 90 minutes away from advancing to the conference finals against either the Galaxy or New York Red Bulls, played its most complete game since May.
Seattle did not have a shot on target, although RSL caught a break late in the first half when Alvaro Fernandez's point-blank header attempt went wide right.
"Yeah, I was very, very pleased," Kreis said. "For me that was a complete match, and we haven't had a complete match of good soccer and good focus and the requisite commitment for a very long time."
Injuries to defenders Nat Borchers and Jamison Olave were the only negatives to come out of the game. Both are questionable for Wednesday.
Chris Schuler came off the bench for Olave and played well.
"Let's credit Chris Schuler," RSL defender Chris Wingert said. "Guys like him don't get enough credit."
As for the positives, there were plenty, including the combination of Kyle Beckerman and Javier Morales. Two of RSL's best players hadn't been on the field together since spring. Their influence was obvious on defense as well as offense.
Morales, closing in on 100 percent since his ankle injury in May, was magic on the ball with two assists, both resulting in goals by Alvaro Saborio.
"To me, he makes things look really easy," Wingert said of Morales. "The guy is so classy, he can slow the game down in his mind when everybody else is so hectic."
The final punctuation came from Ned Grabavoy, one of a handful of RSL players who had been nursing injuries. He came off the bench late and scored the final goal, thanks to a peculiar bounce of the ball, the kind that had plagued RSL in the past.
"It looked good," Grabavoy said of RSL's effort. "It's such a weird thing, you go into the playoffs and, obviously, we hadn't been doing our best stuff, but we kept telling ourselves if we keep playing and working through it that the soccer's going to show through. It doesn't necessarily surprise me. This is a very veteran group, and I thought it would turn around."
P Real Salt Lake at Seattle, Wednesday, 8 p.m., ESPN2