The in-form Belgium with four goals already in the Premier League turned provider as Christian drilled home from 20 yards as we toppled the Saints 1-0 at the Lane.
“He shot twice on target before that and if you keep going, one will go in,” said Nacer, goalscorer at Arsenal last week. “I just had to set up the ball for him and he did well.”
Christian added: “I got the ball from Nacer, great timing and speed, took a good touch and if you shoot between a defender’s legs the goalkeeper will never get there, luckily it went in.”
Nacer struck the post soon after as we had the better of the first half.
Southampton came back into the game in the second half, Hugo Lloris saved well from Victor Wanyama and Sadio Mane missed a late chance to level.
"Of course, you have to look at how you play but the three points was most important and we were good enough," said Christian.
Both players now join their respective counties for Euro 2016 qualifiers - Nacer is with Mousa Dembele and Jan Vertonghen in the Belgium squad to face Andorra and Bosnia-Herzegovina while Christian and Denmark take on Albania and Portugal.
Nacer underlined the importance of winning before the players depart for international duty - with a trip to City next for us on their return on Saturday, Ocotber 18.
“Everyone has to be ready,” he said. “We know they are a strong side but we’ll be organised and show what we can do.”