The Mali international scored the decisive goal in the 70th-minute as City secured all three points in what was the 450th league fixture played at the MKM Stadium.
Head Coach Liam Rosenior made just one change to his starting XI to the one that drew 4-4 against Sunderland on Good Friday as Malcolm Ebiowei replaced Traoré.
The Tigers had the first opportunity of the game in the sixth minute as Ebiowei picked out Ozan Tufan at the back post, but the midfielder could not keep his header downwards as the attempt went over the bar.
The Turkish international drew the first save of the game as Regan Slater’s deflected shot fell into the path of Tufan. Switching the ball onto his right-foot, the 28-year-old saw his effort held by ex-Tiger George Long in the Millwall goal.
Billy Mitchell then tried his luck from range, with his powerful strike going over the bar before Karl Darlow was called into action. Tom Bradshaw’s low cross found Oliver Burke at the front post, but the midfielder’s close-range attempt was blocked by the outstretched hand of Darlow. Burke then smashed the crossbar with a thunderous effort that bounced on the goal line before Alfie Jones cleared away the immediate danger.
The visitors were creating the better of the chances as the first half continued as ex-Tiger George Honeyman floated a free-kick delivery towards the back post for Shaun Hutchinson, but the Millwall captain could not keep his header down.
Danny McNamara was next to have a effort, which was off-target before Darlow produced two quickfire saves to deny Millwall the opener in the closing stages of the first-half.
Rosenior made a triple substitution at half-time, bringing on Traoré, Callum Elder and Ryan Longman, with the latter almost opening the scoring on the 55th-minute. The winger drove down the right wing on the counter before cutting inside onto his left foot, but the curling effort went narrowly wide past Long’s right-hand post. At the other end, both Sean McLoughlin and Elder charged down Mitchell’s shot to block.
The Lions’ midfielder tried his luck again from range, with the shot flying over the crossbar, before the Tigers netted the opener with 20 minutes left to play. Traoré received the ball on the edge of the Millwall penalty area, switching the ball onto his left-foot. The Mali international placed his low effort into the bottom corner past the dive of Long.
Millwall searched for an equaliser minutes later as Bradshaw’s attempt was blocked before the rebound by Mitchell was dragged wide of the right-hand post.
With 10 minutes left to play, Burke fired over after good initial build-up play before Darlow produced a big save to parry away Andreas Voglsammer’s cross-shot at his near post. A minute later, Darlow produced more heroics to deny Bradshaw acrobatically.
In stoppage-time, Traoré searched for his brace, but his right-footed attempt went over the bar before Darlow produced one final save to deny Voglsammer at his near post. From the resulting corner, substitute Romain Esse headed over with the last chance of the game.
Hull City (4-2-3-1): Darlow; Coyle (C), A. Jones, McLoughlin, Greaves (Elder 46’); Seri, Slater; Ebiowei (Traoré 46’), Pelkas (Longman 46’ (Simons 89’)), Allahyar; Tufan (Docherty 83’).
Subs Not Used: Ingram, Woods.
Millwall (4-2-3-1): Long; McNamara, Hutchinson (C), Cooper, Wallace (Malone 89’); Mitchell, Saville (Watmore 82’); Honeyman (Esse 64’), Flemming, Burke; Bradshaw (Voglsammer 82’).
Subs Not Used: Białkowski, Evans, Shackleton.
Attendance: 20,069
