It looked as if Marcus Rashford had rescued a point for the visitors when he capitalised on a blunder from Forest keeper Matt Turner 12 minutes from time.
In the second half, Oparanozie, who also scored Nigeria's winner against South Africa in their semi-final, hit the decisive goal again when she broke the deadlock seven minutes from time.
The Cherries thought theyhad pulled a goal back through Antoine Semenyo but his strike was ruled out for a foul on David Raya by Solanke in the build up.
Perhaps spurred on by that challenge, Celtic quickly took the lead as Matt O'Riley superbly setting up Kyogo Furuhashi to score - just as he had done against Lazio on matchday two.
Nigeria had put ten goals past their opponent whenthey met in the reverse fixture earlier and this was expected to be a stroll in the park for the Super Eagles - exactly how it turned out on the night.
Rashford's cool finish after Greenwood had slotted in from Alex Telles' cross made it three goals in 13 minutes as United moved two points behind leaders Tottenham.
Mikel Arteta's side dominated the first half, with Martin Odegaard hitting the bar while Reis Nelson and Kai Havertz also had chances to give Arsenal reward for their pressure.
Luton thought theyhad the three points when former Manchester United midfielder Tahith Chong tapped home past Alisson on the counterattack after good work from Issa Kabore - as Liverpool players complained for a handball by Ross Barkley from
They were reduced to 10 men when Reece James was shown a second yellow card for a foul on Gordon, before the former Everton man completed the scoring late on.
Bournemouth, who remain 12th, thought theyhad been awarded a late penalty but, following a lengthy video assistant referee (VAR) review, Kambwala's foul on Christie was determined to have taken place outside the box.
The Argentine has had mixed fortunes at Chelsea. With a number of young players signed, and a large number of injuries to the squad, their league form has been inconsistent.
Shortly before the interval, Sergio Romero was out quickly to paw away a clean-through Jota's effort after Wolves had countered quickly from a United corner.