The Saints' recent injury travails meant the 19-year-old was started by boss Ronald Koeman against Roberto Martinez's side - and things couldn't have gone better for the young midfielder or the side as a whole.
And, after the Everton win, Reed took to Twitter to celebrate a day he will never forget:
Amazing performance from the boys today, back to winning ways. Fans were unbelievable too a day I'll never forget #saintsfc— Harrison Reed (@HarrisonReed) December 20, 2014
Meanwhile, his manager also hailed the 19-year-old's spirit and energy after his debut, praising a 'fantastic' display.
“One of the reasons to put him in was because he’s that type of football player with the spirit,” Koeman told Southampton's official Youtube channel. “That gave the team a lot of energy and we needed that energy. He gave a fantastic performance.”
Needless to say, while it was a miserable day for Everton fans, Southampton supporters were overjoyed to be back to winning ways - and they were impressed by Reed, in particular, too.
The Saints' famed youth academy appears to have found another gem in the midfielder and he showed real maturity against the Toffees on Saturday afternoon. Here's a selection of the best fan reactions on Twitter to the Southampton youngster's display!
Great spirit and performance from lads today. Harrison Reed had a quality game. #saintsfc— Matty Brown (@Matty_Brown94) December 20, 2014
Harrison Reed was a little beaut today wasn't he #saintsfc— Pat Lucas (@Pat_Lucas96) December 20, 2014
Good performances all over the pitch today but Reed was especially impressive. So many positives to take from that game. #saintsfc— Phil (@philster82) December 20, 2014
Harrison reed was immense today, with all these injuries why on earth has koeman not played him #saintsfc— JustAnother (@SaintsOpinion) December 20, 2014
Massive 3 points today for #saintsfc Harrison Reed was immense on his first PL start!— Oli Cork-Prowse (@olihoook) December 20, 2014
Good game v Everton impressed with Reed another diamond. Long had good game but all team did well.looking forward to place now #saintsfc— Steve Ingate (@stephenjohninga) December 20, 2014
Yoshida, Long and Reed were all fantastic today. Worked their socks off #saintsfc— Harvey Seymour (@HarveySeymour) December 20, 2014
Great performances all round. Yoshida, Fonte, Alderweireld solid.Reed looked good. Such a difference from Tues. Normality resumed! #SaintsFC— Russell (@RussellSFC) December 20, 2014