Greenwood gave United the lead at the Amex, bamboozling defender Lewis Dunk with his quick footwork before drilling home to send his side on the way to a 3-0 victory.
And as the 18-year-old celebrated he made an 'A' sign with his fingers - a tribute to fellow teenager Gomes, who is set to become a free agent on Wednesday after failing to agree a new contract.
Gomes, 19, took to Instagram to post a thankyou message to pal Greenwood, after the two came up through the rabks together at United.
The attacking midfielder posted a picture of Greenwood's celebration, along with the caption said: "No words! I love you bro.
"Special special player, thanks for the dedicated goal."
And Greenwood posted back, telling Gomes: "A promise is a promise."