(Photo credit: Thomas Shea)

Lukas MacNaughton scored a last-gasp winner in the seventh minute of second-half stoppage time for visiting St. Louis City, who defeated the Houston Dynamo 1-0 in both teams' regular-season finale on Saturday evening.

MacNaughton's goal, coupled with Ben Lundt's six saves, secured the Western Conference's No. 3 seed for St. Louis (15-10-9, 54 points) in the MLS Cup Playoffs. It will face sixth-seeded Los Angeles FC in the first round. St. Louis City also snapped a five-match winless streak (0-4-1) with the victory.

Houston (14-11-9, 51 points) finished with the No. 5 seed with its second straight loss and will take on the fourth-seeded San Jose Earthquakes.

St. Louis had several looks at goal throughout the evening, but failed to put a shot on target until the final kick of the match. After a Houston giveaway, Alex Matan raced up the field and into the box, where he shook off a Dynamo defender and fed it to MacNaughton.

The Canadian international defender unleashed a first-time shot that sailed past Houston goalkeeper Jonathan Bond for the winner, moments before referee Allen Chapman blew for full-time.

Neither team found the net in the first half, as both defenses withstood the early pressure. The Dynamo had the lone shot on goal of the period, a shot from just beyond the penalty area from Guilherme that was stopped by a diving Lundt in the 21st minute.

In the 55th minute, Guilherme caught up to a long ball and ventured in on goal, but Lundt made himself big to erase the chance.

St. Louis gradually grew into the second half and nearly opened the scoring in the 69th minute, but Rafael Navarro's touch on a Jeong Sang-Bin delivery sprayed just wide of the net.

Lundt came through once more in the 86th minute, handling a long-distance shot by Duane Holmes and a header from Duncan McGuire.

In the 89th minute, Damion Downs headed an attempt goalward from a Tomas Totland cross, but missed wide. Moments later, in the second minute of second-half stoppage time, Downs came up big defensively, clearing away a dangerous near-post attempt by Agustin Resch.

That, plus Lundt's big night in net, set up MacNaughton's late heroics to send St. Louis to victory on the final day of the regular season.

--Field Level Media