The two young starlets are set to play together for the Young Lions at the European under-21 Championship this month. But they clashed just two weeks ago while on loan at their respective Championship clubs - Zaha at Crystal Palace and Chalobah at Watford.
The United winger came out on top that day, helping his boyhood club to the Premier League in his final appearance as an Eagle.
But Chalobah had the edge on the table, sending his under-21 teammate packing after a day's training ahead of their first match against Italy on Wednesday evening.
Video shot by Nottingham Forest midfielder Henri Lansbury shows Chalobah celebrating his win, before Zaha storms off in a strop - he's got a smile on his face though.
The two young England youngsters will be hoping to make an impact at their respective parent clubs next season, and Chalobah took to Twitter to welcome Jose Mourinho's appointment as new Chelsea boss.
Check out the video from FATV below...