Updated

Real Salt Lake has dominated the Rocky Mountain Cup rivalry against the Colorado Rapids recently, and the latest edition will help determine the Western Conference leader after five weeks in MLS.

Real Salt Lake sits atop the conference with four wins from five matches, but both Colorado and the San Jose Earthquakes are three points off the pace with three wins from four matches.

Real Salt Lake turned a 1-0 win over the Montreal Impact on Wednesday into its three-point cushion, and hosts Colorado on Saturday at Rio Tinto Stadium.

RSL is undefeated in six straight against the Rapids, and will try to maintain its edge in the rivalry and in the standings with a better performance than in mid-week against the Impact.

Despite the win over Montreal earlier this week, RSL coach Jason Kreis was not happy with his club's performance.

"I don't think it would be hypocritical for me to come in here and say that I'm way pleased, because I'm not. We lost a game a few weeks ago (against Chivas USA), and I was pleased with the performance and displeased with the result; tonight I'm just displeased with the performance," Kreis said.

"It's the first game this year that I can say that honestly. Lots of things to be displeased about and only one to be pleased with, which is three points."

Real goalie Nick Rimando posted his second shutout against Montreal, and felt the club did well to grind out three points.

"Today really wasn't a pretty game, but good teams grind out those wins and we got the three points. That is what matters," Rimando said.

Real Salt Lake (4-1-0) has suffered its lone defeat at home this year, a shock 1-0 loss to Chivas USA on March 24. Otherwise, the club has defeated the Los Angeles Galaxy, Red Bull New York, the Portland Timbers and Montreal.

Kreis expects Real to resemble its previous form from its first four games, as it looks to establish itself atop the standings early this season.

"I expect and demand a better effort from all the guys, and I'm quite certain I will get it. It should be a great game because Colorado is a very good team this year," Kreis said.

"They are looking ... different than they have over the past several seasons, and maybe it will be a beautiful soccer game."

Colorado (3-1-0), under first-year coach Oscar Pareja, is also off to a great start with wins over the Columbus Crew, Philadelphia Union and last week, the Chicago Fire.

Although their lone loss, 4-1 at Red Bull New York, is tough to overlook, the three wins are also tough to overlook.

Colorado has injury problems, as midfielder Pablo Mastroeni has been lost for at least six weeks with post-concussion symptoms. He suffered the initial blow last season in a collision with Real defender Jamison Olave.

Pareja will need Omar Cummings to continue to produce as the striker has goals in his last two games. But after scoring two goals in his first three games of last season, Cummings had just one more in the regular season.

Cummings knows Colorado needs him to produce, especially against RSL.

"As a forward, you always feel pressure to get the ball in the back of the net," Cummings said. "That is your main job description. To see them going in in any way, you'll take it."