"I thought I played really well tonight," BBC Sport quotes Federer as saying.
"You've got to bring your best game [against Tsonga] because he dictates play a lot. I think I did a good job dictating play.
"Jo does that to you, he makes you play aggressive, because if you don't he will. I thought the tactics worked well tonight. We spoke about it before the match. I don't go to matches unprepared before like I used to."
Federer will take on Andy Murray for a place in the semi-finals.