Sporting Kansas City is still perfect.

Aurelien Collin scored in the second half and Kansas City posted its fifth shutout through six matches, 1-0 over Real Salt Lake on Saturday in a battle of the top two clubs in Major League Soccer at Livestrong Sporting Park.

Sporting (6-0-0) extended its record streak of not allowing a shot on goal to 335 minutes, which lasted until Real (5-2-0) tested goalkeeper Jimmy Nielsen in stoppage time.

Kansas City has allowed just one goal this season in one of the best start's in the league's history, as center backs Matt Besler and Collin have made it easy on Nielsen to this point in the season.

Sporting controlled the match up of Eastern and Western Conference leaders, and nearly pulled in front late in the first half when C.J. Sapong headed a shot past RSL goalie Nick Rimando.

Referee Kevin Stott waved the goal off due to a foul on Sapong, but Sporting treated a crowd of 19,422 to match-winner in the second half.

Graham Zusi swung a corner kick in from the left, and Collin sneaked unmarked to the edge of the six-yard box to power a header past Rimando from close range for his second goal of the season. Zusi's assist was his MLS-best sixth.

Although Sporting's scoring threats were also rare, Zusi almost produced a second goal in the 75th minute off another corner, but Kei Kamara had a strong header from just six yards denied by a sprawling Rimando.

Sporting did not allow a shot on goal in its last two games, wins over Chivas USA and the Los Angeles Galaxy, and made it into stoppage time before Nat Borchers put a header on goal against Real.

Kansas City allowed its only goal this season against FC Dallas on March 25, and that was the last shot on goal before Borchers' attempt. Nielsen has been in goal for all six matches this season.

Sporting will try to extend its amazing streak Wednesday in Canada against Vancouver Whitecaps FC. Real visits the San Jose Earthquakes in a battle of the top West clubs April 21.