Dimitar Berbatov opened the scoring in the first half and although Kevin Nolan equalised straight after the break, Hugo Rodallega replied immediately and Joey O'Brien's injury-time own goal sealed the win.
The Hammers pushed hard for an equaliser prior to that third goal and Jol was full of praise for the way his team held on for the three points.
"They didn't play on Saturday and you could see that," Jol told Sky Sports. "I had a few tired players second half. The defenders played like heroes. They put us under pressure.
"We said on the bench they would bully us and they scored straight away after half time. We didn't pay attention and it's not the first time.
"Then we got the goal, which was great, but we couldn't keep the ball and that's what you want - the first pass forwards you should keep and then everyone can exploit the space.
"But I'm a happy man because we needed these three points."
Jol opted to pair Berbatov and Rodallega up front after using the former as a lone striker in recent weeks and the Dutch coach revealed the thinking behind the decision.
"We needed a striker today to play off the shoulder and to stretch them because we analysed them," he added.
"And obviously we knew what happened at their place when Berbatov came on and we played much better so we did the same today. We were lucky that it paid off."