The Conference-leading Sounders will play host to the defending MLS champions at CenturyLink Field in Seattle, with just two points separating the two teams.
Seattle moved to 26 points from 13 games after salvaging a 2-2 draw at the Vancouver Whitecaps last week.
Nigerian striker Obafemi Martins has been a key player this season, having scored five goals, though it has not been all that smooth for Sigi Schmid's men.
Before the Sounders edged the San Jose Earthquakes on May 17, they were on the receiving end of a 5-0 drubbing at the hands of Eastern Conference pacesetters the New England Revolution.
But the Sounders, who are without captain and leading scorer Clint Dempsey (FIFA World Cup duty), will face an even sterner test against an unbeaten Real Salt Lake outfit, led by Jeff Cassar.
After four draws from their opening seven games, Real Salt Lake have clicked into gear, winning three of their past four.
Those wins included triumphs over Chicago Fire (3-2), Houston Dynamo (5-2) and Colorado Rapids (2-1).
Although, Seattle have not lost at home to Real Salt Lake since May 2012, when Fabian Espindola - now plying his trade at DC United - netted the match-winner.
Meanwhile, in-form New England can extend their winning streak when they travel to Eastern Conference cellar-dwellers Montreal Impact on Saturday.
New England have won five games on the bounce heading into their trip to Stade Saputo, sweeping Sporting KC (2-0), Toronto (2-1), Seattle (5-0), Philadelphia Union (5-3) and DC United (2-1) along the way.
The Revolution have scored 16 goals during that run, with back-to-back five-goal performances against the Sounders and Union.
And they will be full of confidence coming up against the Impact, who have only triumphed once this season.
In other fixtures on Saturday, Sporting KC will be out to snap a four-game winless streak when they face fourth-placed DC United in Washington.
Ryan Nelsen's Toronto FC go head-to-head with Columbus Crew at BMO Field.
Free-falling Dallas are without a win in seven games and the SJ Earthquakes will be aiming to take full advantage of their decline when they make the trek to Texas over the weekend.
As for Western Conference's basement club Chivas USA, they play host to Philadelphia Union.
On Sunday, the LA Galaxy could rise as high as fourth in the standings - depending on results - if they get the better of the Chicago Fire on the road.
Colorado Rapids will be hoping to build on their rout of the Impact when they welcome Houston Dynamo to Dick's Sporting Goods Park.
While the Whitecaps and Portland Timbers square off in their mid-table clash in the West.
