Chris Seitz had four saves to help FC Dallas tie Real Salt Lake 0-0 on Saturday night.
FC Dallas (15-8-8) has played two ties since beating New England on Sept. 13, and stretched its lead to five points over Colorado and the Los Angeles Galaxy atop the Western Conference.
Real Salt Lake (12-10-9) is 0-2-1 and has not scored in its last three games, yet remains in fourth place in the Western Conference.
FC Dallas midfielder Mauro Diaz hit the post in the 8th minute. Real Salt Lake's Joao Plata fired a right-footed shot from outside the 6-yard box to the near post, but Seitz had a diving, fingertip save in the 85th minute.
Real Salt Lake's goalkeeper Nick Rimando had two saves, including a first-half free kick and a header from Walker Zimmerman.
RSL is 1-12-3 at FC Dallas in league games.
