The Argentine struck for three of San Jose's four goals in their first win of the campaign, which saw the Quakes erase two deficits en route to all three points at PayPal Park.
With his team trailing 2-0 on the stroke of halftime, Espinoza got his first of the match with a first-time volley from close range. Then, after Jordan Morris made it 3-1 with a goal in the 57th minute, Espinoza added his second with a driven cross from the right side that fooled Sounders goalkeeper Stefan Frei and skipped into the net.
With the match looking bound for a 3-3 draw, Espinoza instead found the winning goal from the penalty spot just before the final whistle, successfully converting after Nouhou was whistled for a foul in his own area on Video Review.
San Jose were playing in their first match since the departure of head coach Matias Almeyda. The three points should offer some positive momentum as the Quakes start life under interim head coach Alex Covelo.
They'll return Sunday at New York City FC (1 pm ET | MLS LIVE on ESPN+), with the 27-year-old in his fourth season at San Jose. He has 12g/33a in 93 games (88 starts) for the club after originally joining on loan from La Liga side Villarreal.
The MLS Player of the Week is selected each week of the regular season through both media and fan voting in a process conducted by MLS Communications. A panel of journalists from the North American Soccer Reporters (NASR) comprises 75 percent of the vote, while a Twitter fan vote represents the remaining 25 percent of voting. NASR consists of members of print, television, radio and online media.