The Cottagers gave as good as they received, but ended up 3-1 losers at Craven Cottage.
Jol said: "They scored two goals out of the blue, because I don't think they had a lot of chances in the first half.
"It (Giroud's goal) was a little bit of luck. At first I thought it was offside.
"Then we took the initiative and they scored (through Lukas Podolski).
"They almost play better nowadays away from home, because they have all the players, in a transitional game, to hurt you.
"You have to take your moments, you have to take your chances, you have to be more greedy. We lacked a cutting edge up front."
Jol was pleased with the performance of Bent off the bench and another debutant, midfielder Scott Parker.
"There were a few positives, but it's very disappointing to lose your first home match," Jol added. "If you look at the positives, Bent scored. Scott Parker did ever so well. He did exactly what I wanted of him."
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