Belgian international Hazard has said that while the victory over the Baggies was a "good response", the club must do everything to achieve their aim at the end of the season.
"It was a good response to the two losses," the 27-year-old told Chelsea's official website. "We have great players and we need to finish in the top four at the end of the season, that's our target.
"We have 11 games to play between now and then and we have to give everything to achieve that. We are all together. We have to work and win games. When you play for Chelsea you have to put this in your mind and give everything on the pitch.
"We need to be in the top four, for the Champions League next season, and it would be good if we can take the FA Cup. We are also in the Champions League, it's not easy to win the Champions League but we will go for everything."
Chelsea's European adventures continue next week with a last-16 tie against Barcelona.