Ghana international Antoine Semenyo scored and provided an assist as Bournemouth came from behind to beat managerless West Brom and move into the FA Cup fourth round.
The Baggies, led by caretaker boss Chris Brunt, took the lead when Caleb Taylor headed in a rebound after Grady Diangana hit the crossbar.
But Justin Kluivert levelled for Andoni Iraola's in-form Premier League side from close range after David Brooks' effort was parried by Joe Wildsmith.
Kluivert then picked out Ouattara with a clever reverse ball and the forward slammed a shot past the keeper from a tight angle.
The Burkina Faso international then ran onto Brooks' ball to cap off a counter-attack and make it 3-1 before the break.
Brooks then picked out Antoine Semenyo, moments after his half-time introduction, to smash in a fourth.
In injury time, Daniel Jebbison scored his first goal for the club from Semenyo's through-ball.
Champions League chasers Bournemouth are now unbeaten in nine games and they will travel to London to face Chelsea in the Premier League on January 14.
Semenyo has now netted six goals and provided three assists in 21 appearances across all competitions for AFC Bournemouth this season so far.
