The defensive effort as well as the result left RSL coach Jason Kreis fuming and without any clear answers as his normally reliable team continued to make mistakes that led to goals.
"I don't know a time that I felt as mad as I do right now," RSL coach Jason Kreis said. "I'll be honest with you, soccer can be a very cruel game. Tonight was every indication of that. We have a ton of chances and we don't finish in their box, and they create a couple of chances and they finish."
Real (10-5-2) squandered about a half-dozen chances to send San Jose packing. Time after time, in front an inviting net, Salt Lake doomed itself with the inability to finish.
"It's disheartening, for sure," Kreis said.
The Earthquakes' (10-3-3) first score came when RSL defender Nat Borchers tangled with Alan Gordon inside Real's 18-yard box. Gordon, who has just entered the game, slipped by Borchers and headed the ball into the net in a short-lived 1-0 lead.
Four minutes later, RSL midfielder Javier Morales tied the game with a beautifully bending ball.
Then, on a San Jose throw-in, poor RSL positioning cost it two 50-50 balls, and Chris Wondolowski banged home the winner.
"Mentally tougher," was RSL midfielder Will Johnson's recipe for beating the team's defensive funk, one that accounted for three goals in a loss Wednesday to the Los Angeles Galaxy.
"I think we're little bit weak right now," Johnson said. "We're not finishing up plays. ... We're not staying sharp and focused. The goals we're giving up are really poor.
"If someone comes in here and beats us, fair enough. But for us to give rivals that are close to us in the table is just unexceptable."
Real Salt Lake had seven shots on target. The frustrating parts, though, were the clear chances in point-blank range with nothing but the goal mouth to shoot at.
Most times players failed to pull the trigger in time.
"They save one or two balls off the line," Ned Grabavoy said. "We created a lot of chances. There's always plays with missed passes or timing not right, but Javier looked bright, sharp."
The first half began with both teams unable to build too much out of midfield.
That lasted about 25 minutes, as slowly RSL began to string passes together.
Morales and forward Fabian Espindola began to create more and more chances. San Jose was fortunate several times that a final touch was too strong or a looping pass into the 18-yard box was a tad too high.
Espindola had Real's first quality chance, finding himself behind the Earthquakes' defense with only the keeper to beat. He took one more touch than necessary and San Jose was able to close the gap.
"Right now we're in a bad way, there's no doubt," Kreis said. "We're cycling downwards. Two games at home to lose, this doesn't happen to us."
Storylines RSL misses opportunities
R Despite 19 attempts on goal Real Salt Lake loses back-to-back home MLS games for the first time at home.
• RSL's Kyle Beckerman picks up a yellow card and is now unavailable for the next game.