Jeffrey D. Allred, Deseret News
Real Salt Lake forward Robbie Findley (10) takes a shot against Seattle Sounders FC during MLS action in Sandy Saturday, June 22, 2013.
This is a pivotal game in the season. This is a must-win for us. —RSL defender Tony Beltran

SEATTLE — As far as September MLS matches go, they don’t get any bigger than this.

With soccer fans across the country still buzzing about the United States’ World Cup-qualifying win over Mexico on Tuesday, the top two teams in MLS square off on national TV this Friday in a match that may ultimately determine the Supporters’ Shield winner.

Perhaps it’s premature to declare that the Supporters’ Shield will be won in Seattle with seven weeks remaining in the regular season — but then again, maybe it isn’t.

Visiting Real Salt Lake holds a two-point cushion over Seattle in the race for the best regular-season record, but the Sounders have two games in hand and have won seven of their last eight. A win for either team would be a huge shot in the arm, momentum that could easily carry either franchise to its first Supporters’ Shield trophy.

“This is a pivotal game in the season. This is a must-win for us,” said RSL defender Tony Beltran.

Real Salt Lake is 2-0 against Seattle this season, but both matches were played at Rio Tinto Stadium. Friday’s match will be at CenturyLink Field, where more than 55,000 fans are expected to be on hand for the top-of-the-table clash (NBCSN, 8 p.m. MDT).

If RSL can steal the victory, coach Jason Kreis’ team might be impossible to catch in the Supporters’ Shield race regardless of games in hand by Seattle and Montreal.

After Friday, Real Salt Lake’s final five regular-season games are against teams that sit fifth, sixth, seventh, eighth and ninth in the Western Conference standings. Seattle, meanwhile, faces a very difficult schedule that includes Los Angeles twice, Colorado and New York. Montreal faces a tough schedule as well over the final seven weeks and must juggle two Champions League games.

First, however, RSL needs to get a result in Seattle.

“It’s always a terrific crowd there, extremely noisy, passionate fans. It’s a place our guys feel great about going to, and they always rise to the occasions there and give us great performances, and I expect nothing less on Friday night,” said Kreis.

Real Salt Lake hasn’t played a match in 13 days, and Beltran said he’s anxious to get back and try and build on the momentum from a 4-2 win over Portland on Aug. 30.

“Very much looking forward to this game, it was good to get a little bit of rest, but after a couple days you’re ready to get back at it,” said Beltran. “It was a long two weeks, and I think the boys are fresh and geared up for Friday. It’s going to be a huge affair.”

Seattle is 5-1 since it signed Clint Dempsey in early August — which includes recent wins over Chivas USA and Chicago while Dempsey was away with the U.S. national team.

“They’ve got some really nice momentum going, and they’ve been able to win in several different ways — been able to win them pretty, been able to win them ugly. But they’ve just been continually able to go along and get points,” said Kreis. “I think momentum is the biggest thing in their favor right now.”

Both Dempsey and Eddie Johnson are back with Seattle after playing big minutes with the United States on Tuesday, as is Real Salt Lake midfielder Kyle Beckerman. Kreis hasn’t shied away from starting Beckerman on short rest in the past, and it’s hard to imagine his captain won’t be in the starting 11 with so much on the line.

Salt Lake striker Alvaro Saborio is out with a calf strain picked up with the Costa Rican national team, but RSL’s depth has allowed it to enjoy plenty of success without its leading scorer.