Kreis responded to RSL's fourth loss in fifth games with warnings of possible roster changes.
"Quite frankly, a lot of [the players given the opportunity to play] have not gotten the job done," a dejected Kreis said during his post-game radio interview. "There will be a lot of difficult decisions to make at the end of the season."
With time running out in the third minute of extra time, Houston rookie Alex Dixon took advantage of a poor defensive marking by RSL defenders to deliver a left-footed winner from outside the 18-yard box into the top corner of Salt Lake's goal.
The loss wasted a brilliant effort by Fabian Espindola, who scored RSL's first goal and assisted on the second. It also highlighted a wasted opportunity in front of a wide-open Houston net by Luis Gil.
Gil did respond and put RSL in front 2-1 in the 60th minute, but miss could have given RSL a two-goal advantage.
Instead, Bobby Boswell tied the game nine minutes later on a corner kick, heading in Brad Davis' cross.
The rest of the way, a passive RSL pinned its hopes for at least a point on goal keeper Nick Rimando.
""We were holding our own," RSL's Andy Williams said. Nick made a few great saves for us and we just let him down."
Kreis refused to blame the muggy, 93-degree heat for RSL's wilting defensive effort during the final 25 minutes. Houston, firing at will, put eight shots on goal in the second half.
"We're heartbroken, there's no doubt about it," he said. "You look around the locker room, and all of us are feeling devastated about that, because you never want to be in a position where you have two leads and walk away with nothing. We would have at least liked to get the draw, and if we're 30 seconds better there at the end, we walk away with at least a point, and we can pat ourselves on the back for all the hard work that we put into that. But to walk away with nothing, it feels very, very unfortunate."
Despite playing its third game in a week, the surging Houston Dynamo (8-7-11) are now unbeaten in their last five home games, scoring 11 goals during the run.
Meanwhile, RSL (10-7-6), which hadn't scored an away goal in more than 300 minutes, broke the streak in the 28th minute. Real took a 1-0 lead into halftime, but needed just two minutes of the second half to lose it.
Brian Ching scored the equalizer for Houston with a laser 35 yards from goal.
With RSL facing a third consecutive road game at Chivas USA next week, Kreis was left to ponder what has become of his once powerful team.
""We conceded a soft goal," Kreis said. "Once we've done that, the momentum is going against us. Rather than getting out there in the second half and getting on our front foot like we did at the beginning of the first half, we didn't get that done, and from that moment on we're reeling a bit."
R Houston rookie Alex Dixon keeps RSL winless at Robertson Stadium with a winning goal in the waning seconds of extra time.