McCormack took less than two minutes to score his fifth goal in four appearances against Huddersfield.
Town skipper Mark Hudson equalised before half-time with his second goal in four days but Fulham were good value for the away point.
Serbian Jokanovic had lost his first three games in charge but top scorer McCormack wasted no time in settling Fulham nerves.
McCormack, a target for promotion-seeking Derby in the January transfer window, had four goals in his previous appearances against Town, including a hat-trick for former club Leeds.
The striker will not have scored many simpler goals this season after an awful blunder by Town midfielder Jonathan Hogg.
Hogg attempted a long crossfield ball across the back line. He failed to lift his pass and instead rolled it to the unmarked McCormack who slotted past the helpless Jed Steer.
Town almost levelled eight minutes later when Jamie Paterson cut in from the left, side-stepping a defender, but his drive came back off the inside of the far post. Joe Lolley was unable to control the rebound.
Fulham had the ball in the back of the net again in the 16th minute but McCormack was ruled off-side as Alex Kacaniklic fired home.
Fulham had claims for a penalty when McCormack went down under challenge from Hudson but referee Christopher Sarginson waved play on.
Town equalised in the 20th minute with Hudson’s second of the season when he converted Emyr Huws’ free-kick. Huws drifted the ball invitingly for centre-back Hudson to stick out a boot and steer a finish past Andy Lonergan and into the far corner.
McCormack had another sight of goal after Jamie O’Hara’s free-kick from the right but his shot was blocked by Hudson’s lunge.
Huws curled an effort wide for the home side and close to half-time Nahki Wells was clean through and faced down Lonergan but a brilliant saving tackle from Dan Burn kept the scores level.
Early in the second half Lonergan pulled off a superb double save when he got down low to save from Wells and then produced an even better instinctive one-handed stop from Harry Bunn.
O’Hara’s shot had the sting taken out of it by Hudson and Steer had an easy save but Fulham kept possession well and had a great chance to win the game.
In the 70th minute Lasse Vigen Christensen found space to cross from the left and sub Moussa Dembele, on at half-time, was free in the box but headed wide.
Paterson tested Lonergan again at his near post but overall Town failed to spark and Fulham held out.
Town head coach David Wagner said: “It’s good but we have to analyse our performances game by game.
“This was a very different game to Tuesday when we beat Charlton 5-0. We have to be open and fresh to new ideas.
“After the game I accept the result and I am not unhappy with a point. With the way we started it was not easy.