The Belgian winger claimed his second Premier League assist as he set up Julian Alvarez for the opening goal before Erling Haaland added the second.
Doku was named the official player of the match after he constantly attacked right-back James Milner, who was substituted at half-time with Dickov joking that he almost felt sorry for the former City player.
The 21-year-old joined from French side Stade Rennais on a five-year deal in the summer and has already made a big impact in the opening months of the season.
“He’s settled in better than anyone would have expected,” Dickov said on Matchday Live’s post-match analysis.
“He’s a young boy, not used to this style of play and came from midtable in France. Usually when we sign players, they are playing at the top level in whatever country they’re in.
“I’m pleasantly surprised how he’s settled in, he looks a threat every time he gets the ball. I joked at half-time that I felt sorry for James Milner.
“At times there’s a little bit of naivety and what Pep will be putting into him is that he can’t beat his man every time he gets the ball.
“Sometimes, like when Jack [Grealish] came on, you just slow the game down under pressure and keep the ball when that’s what Pep wants to do.
“But he’s been super impressive since he came in and for someone so young.”
While Doku was a constant menace in the first half, the Seagulls improved after the break, pulling a goal back and chasing an equaliser following a second yellow card for Manuel Akanji.
But City saw out the game to claim the three points to move back to the top of the Premier League and fellow Matchday Live guest Steve Howey said they can take positives from digging in.
“They got a goal and it was bit nervy and then there was the sending off as well,” the former City defender said.
“Sometimes for the team that wins the Premier League, you’re not going to win all the time or easily and at a canter.
“Sometimes it has to be ugly, sometimes it has to be hard and it’s a graft, you have to dig in and that’s what they did and they got the three points.”