The 22-year-old got the first hat trick of his MLS career and an added an assist to pace the Cityzens to the emphatic victory, opening the scoring in the 12th minute before adding two late insurance goals. He provided the helper on teammate Gary Mackay-Steven's goal in the 42nd minute.
Castellanos kicked off the five-goal outburst 12 minutes into the match, heading home a feed from teammate Maxi Moralez inside the left post.
After NYCFC relinquished the lead and fell behind 2-1, Castellanos assisted on Mackay-Steven's equalizer with a nifty touch that sent the Scottish midfielder in on goal for the finish.
Following a golazo from Alex Ring that put the Cityzens back on top, Castellanos provided the dagger in the 76th minute, cashing a feed from Jesus Medina into the top right corner to make it 4-2. The Argentine would then round out the hat trick with an 84th-minute penalty kick for NYCFC's fifth goal.
The victory moved NYCFC to 11-8-3 on the season, giving them 36 points from 22 matches and leaving them in the No. 5 spot on the Eastern Conference table, where they've clinched a playoff spot.
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.