Victor Rodriguez scores for Seattle in the first half. (Jennifer Buchanan/USA TODAY Sports)

SEATTLE — Get ready for an MLS Cup rematch.

Seattle Sounders FC made sure of that at CenturyLink Field Thursday night.

The Major League Soccer defending champions registered a 3-0 victory over the 10-man Houston Dynamo in the second leg of the Western Conference final series to book a spot against Toronto FC in next week’s championship game.

Sounders FC, which defeated Toronto FC in last year’s final, won the aggregate-goals series, 5-0.

Toronto and Seattle will tussle at BMO Field Saturday, Dec. 9.

Goalkeeper Stefan Frei recorded the shutout as Sounders FC hasn’t allowed a goal in the playoffs while accruing 12 clean sheets in its last 18 matches.

After dropping a 2-0 decision at home in the opening leg, the Dynamo needed to score three goals to pull off an upset for the ages and its task was made much more difficult if not impossible in the first half.

Seattle took advantage of some nifty passing to score on the first shot of the game by either team in the 22nd minute. Víctor Rodríguez latched onto a Will Bruin and powered a 10-yard shot into the left side past goalkeeper Joe Willis for a 1-0 Sounders FC lead.

Tomas Martínez placed the Dynamo’s first two shots on goal in the 40th and 42nd minutes, but Frei was up to the task, diving to his right to deny the midfielder on the former and having little trouble handling the second attempt.

Rodriguez created Seattle’s second goal in the 57th minute as he fed an onrushing Joevin Jones on the left flank. The Trinidad & Tobago slotted a low cross to Clint Dempsey, who had an easy time tapping the ball home for a 2-0 advantage.

The score was Deuce’s seventh playoff goal of his MLS career.

Houston’s hopes of making any sort of comeback was stymied when Martinez was red-carded by referee Hilario Grajeda in the 66th minute after it was ruled that he hit Jordy Delem in the back of his head.

Bruin, who tallied in the first leg, duplicated the feat against his former team Thursday night. He ran onto a Harry Shipp ball and clipped it over Willis or his eighth career playoff goal in the 73rd minute for a three-goal margin in the game and five in the series.