Although Darren Pratley scored a late goal for opponents Bolton Wanderers and there was a further alarm near the end when the hosts hit the woodwork Leeds emerged with a deserved 2-1 away victory in front of almost 7,000 travelling supporters.
United welcomed Sol Bamba back as captain in place of the injured Liam Cooper while Diagouraga came in for his first start since joining from Brentford, replacing Luke Murphy as head coach Steve Evans went with his strongest possible side.
With hamstring victim Chris Wood unable to play, up front it was Mirco Antenucci alongside the back to form Doukara.
And after Gary Madine and Lewis Cook had shots saved at either end it was Doukara who gave Leeds the start they wanted with a goal after nine minutes.
Stuart Dallas played the ball though and Doukara did the rest, beating home keeper Ben Amos with a low shot for his fourth goal of the season.
Bolton could have had hit back soon after when Madine fired over from close range, but United still carried a threat as shown when Dallas got free just inside the box only to shoot over.
Another chance followed on 25 minutes as Cook led a good break and found Antenucci inside the area, but he was denied by an excellent save by Amos.
They did make it 2-0 close to half-time, though, when Antenucci’s cut back was met by new boy Diagouraga, who calmly beat Amos for his first goal in a Leeds shirt.
The second half saw some end to end play with Leeds having the first chance only for Charlie Taylor to mis-hit his shot after being picked out by Cook.
At the other end, Madine’s effort from close range was bundled behind to safety.
United should have put to the tie to bed on the hour as Dallas gave Scott Wootton clear space, but he shot over.
It did not seem to matter as the visitors stayed on the offensive and Giuseppe Bellusci saw his free-kick turned over by Amos.
Bolton put in a big finish, however, and after Liam Feeney hit a shot well over it needed a great Bellusci block to keep out Pratley’s half-volley.
Pratley then found the back of the net nine minutes from time after the ball fell nicely to him from a corner to set up a frantic finish.
Leeds held on, but breathed a sigh of relief three minutes from time as Madine hit the post after Marco Silvestri had only succeeded in pushing Pratley’s strike straight to the home striker.
Bolton Wanderers 1
Leeds United 2
(Doukara 9, Diagouraga 40)
Saturday, January 30, 2016
Emirates FA Cup round four
Bolton: Amos, Vela, Dervite, Holding, Moxey, Trotter, Pratley, Davies (Spearing 69), Feeney, Wellington (Woolery 69), Madine.
Leeds: Silvestri, Wootton, Bellusci, Bamba (Coyle 89), Taylor, Cook (Adeyemi 90), Bridcutt, Diagouraga, Dallas, Doukara, Antenucci (Carayol 86).
Referee: Andre Marriner.