The Dutch coach bemoaned his team's showing in the opening 45 minutes but praised his side's resilience despite their failure to hold on to their 2-1 lead late in the game
Jol's team were denied all three points after Saints defender Jose Fonte headed in his second goal of the day in stoppage time just minutes after Kieran Richardson had given Fulham the lead.
The Dutch coach was happy with his side's application in the second period but was still frustrated with the first-half showing that left them trailing 1-0 after Fonte scored his first goal in the early stages.
"I wasn't pleased with the first or second goal but I was very pleased with the resilience and the character and the mental strength," Jol told Sky Sports.
"Although we were a bit worried in midfield to play, we didn't play, we did better in the second half.
"We stood up and played like we always did before. We put them under pressure and my best players in the second half had the ball – Bryan Ruiz, Giorgos Karagounis, and we played football."
The Fulham chief was also left frustrated by a number of decisions made by referee Mark Clattenburg, with Southampton's equaliser coming after what Jol felt was a questionable free-kick that was awarded to the hosts.
"The ref acted as if he did not see it," he complained. "And then two seconds later it was a free-kick to them. But OK, that happens and of course, if it doesn't they wouldn't have scored."
Striker Dimitar Berbatov was left out of Fulham's squad after struggling with a hip injury but Jol confirmed that the Bulgarian was close to returning to the team.
"He was very close [to playing against Southampton]," he revealed. "He told me on Monday he would probably play and then on Friday he said he didn't want to take a risk.
"He came to me yesterday and he was doing a test today in London and if they [he and Mladen Petric] would have been fit, they would have travelled to Southampton maybe to be on the bench or maybe in Berbatov's case to start. But he is on the fringe of being fit."