Fernando Amorebieta put Steven Gerrard's free-kick through his own goal in the 22nd minute at Anfield on Saturday. The Venezuela international was then shrugged aside for Martin Skrtel to head home a Gerrard corner.
Luis Suarez added a goal either side of the interval and Fulham were ultimately fortunate to escape further damage as Jol's men slumped to a fourth consecutive defeat in all competitions.
"It was a difficult afternoon," Jol told BBC Sport, with his team hovering two points above the relegation zone.
"Goals change games but they scored twice from set-pieces. We then had a big hill to climb and they were the better team.
"After conceding the first two goals it was almost impossible to get back in the game.
"We were not good off the ball - they played around us and we needed more toughness and aggression, which is what we did in the second half.
"This is a side in the top three and four, so you try to get these games out of the way and try to get a result.
"There are a few players who will go off on international duty so that will not help. We couldn't get a good result against a top side.
"The second half was not enough - you can't start like that and concede goals like that. But we are still up for the fight."
