Anthony Elanga had left Manchester United in the past. On Tuesday, they trailed in his wake.
Alejandro Garnacho and Patrick Dorgu could not keep up with the 22-year-old as he burst from the edge of his own area on to Ryan Yates' defensive header, collected the ball and ran 70 yards.
The Sweden winger still had the composure to find the bottom corner from 18 yards.
A special moment - but he refused to celebrate against the club he joined as a 12-year-old.
A 1-0 win maintained Forest's relentless quest to reach the Champions League and left them third in the Premier League, with a 10-point lead over Newcastle in sixth.