The serving from both men last night was immemse. Kyrgios in particular was world class and no player in the world (federer and nadal included) would have prevented a tie breaker from occurring in sets 1, 3 and 4.
The reason Kyrgios serving was slightly superior to Tsonga IMO because it was much more varied and unpredictable but to be fair to Tsonga, he didn't need to change it up because Nick for some reason didn't lean towards the centre after set 2.
Massive match against dimitrov next, the winner will play an unseeded player in the quarter final.