Called in for his first start of the Premier League season, Giroud repaid Maurizio Sarri's faith by teeing up the first two goals of Hazard's sublime treble at Stamford Bridge.
The classy performance continued the France striker's upturn in form after he broke a 10-match international drought with the winner in a 2-1 defeat of Netherlands last weekend.
Hazard highlighted Giroud's physicality, in contrast to that of Alvaro Morata, as making him the perfect partner in attack.
"He's a target man, maybe the best in the world. I think so," the Belgium star told BBC Sport.
"He can hold up the ball... it's a pleasure to play with him. When Alvaro is playing it's completely different, he's a different player to Olivier.
"They both have quality, so we are happy to have good strikers in the team."
Hazard was the driving force in maintaining Chelsea's perfect start to the season, striking twice before half-time to erase Sol Bamba's shock opener and later adding a third from the penalty spot.
The 27-year-old now has five goals in as many appearances this term and credits the hot streak to the sense of creativity Sarri has instilled.
"We have a lot of freedom on the pitch and, at the moment, when we try and do something it's coming off," he said.
"I'm always happy when I'm playing football.
"I just want to do my best for this club, which has done a lot for me. I'm always trying to do more - create more chances, score more goals, and today [I scored] a hat-trick so I will try to do this more."