The ranks of the unbeaten teams left standing in MLS have thinned quickly in Week 8.

This week started with three undefeated teams before league leaders LAFC suffered their first loss of 2019 with a surprising 1-0 midweek defeat to Vancouver Whitecaps FC at BC Place.

The second unbeaten side to go down was the Houston Dynamo (4W-1L-1D) who also fell on the road. Wilmer Cabrera's side conceded a goal with two minutes left as the LA Galaxy prevailed 2-1 on Friday.

That leaves one final team with an unblemished season to date. At 5W-0L-1D, the Seattle Sounders will take their undefeated record into Banc of California Stadium for a nationally televised match against league-leading LAFC (6W-1L-1D) on Sunday night (7 pm ET | FS1 in US; MLS LIVE on DAZN in Canada).

It's a matchup between two of the best teams in MLS after the first seven weeks and it should carry significant repercussions in the Western Conference. LAFC's 19 points have them atop the West, but the Seattle Sounders are just three points behind.

These heavyweights will meet again one week later for the second and final time in 2019 regular season play, facing off in Seattle on Sunday, April 28 (3:30 pm ET on ESPN in USA, MLS LIVE on DAZN in Canada).

Just how tough is it to stay undefeated in MLS? In 2018 the last team to lose was NYCFC, in their eighth game, while in 2017 it was FC Dallas, who lost in their 10th game of the season.

Seattle are at six matches and counting.