Second-half goals from Oscar and John Obi Mikel secured Chelsea the points and Jol acknowledged his team failed to step up after half-time.
However, Bent missed a great chance to score when he was one-on-one with Petr Cech in the first half before keeper Stockdale failed to hold Andre Schurrle's shot in the build-up to Oscar's goal.
However, Jol told Sky Sports: "Darren Bent is a goalscorer and anybody can miss chances.
"If you saw the first 10, 15 minutes, on the right, on the left, we turned our defenders and Cole had problems with Damien Duff.
"We should have stepped up a gear, as they did, in the second half after 50 minutes. Today, especially in the first half, there was maybe a surprise in the air, but we couldn't do anything in the second half, and that was disappointing."
When asked if Stockdale could have done better with Chelsea's first goal, Jol replied: "I feel the whole set-up, we dwelt on the ball and put pressure on Sascha (Riether) by giving him the ball too late and he had no option but to play the ball forward, and they broke us.
"I don't want to blame my goalkeeper. Sascha told me there was a deflection, so it's not as clear as it looked at first.
"He could not hold the ball, but that was a save and it was a bit unfortunate to concede that goal."
Jol continued: "It's always hard if you get away with nothing. After seeing the first half, at half-time I thought we could have done something today, but in the second half they stepped up a gear.
"They were more aggressive than us, and that showed with the first goal and the corner kick with the second goal."