Slavisa Jokanovic felt his Fulham side were worthy winners at Cardiff after claiming a 4-2 victory.
The Whites inflicted a first home defeat on the Bluebirds, who slipped out of the automatic promotion places in the Championship.
Floyd Ayite crossed for Tim Ream to put the visitors ahead in the first-half before he got on the score sheet himself after the break.
A spectacular strike from the returning Bluebirds striker Kenneth Zohore offered Cardiff hope, but Ryan Sessengon restored Fulham's two-goal advantage.
There was time for late drama with Callum Paterson pulling another goal back for Cardiff in stoppage time before Stefan Johansen sealed victory for Fulham with virtually the last kick.
"We played well," Fulham manager Slavisa Jokanovic said. "We scored four goals and created more chances.
"We defended well and tried to hold the line high. The team showed great spirit with the ball and also without.
"We were more clinical today and showed we can be more solid in defence. It's a tough trip for all teams to come to Cardiff. They are a solid and strong team, but it's only three points.
"It's important for supporters because they like to win on Boxing Day. We showed we can be competitive in this league. I hope we can achieve three points in the next game. Where we finish at the at end of the season, I don't know.
"We must keep going and we can improve. Some games like today give us encouragement.
"We believe we can be competitive in this league and achieve our targets."