Put two of tennis' most explosive servers together and expect fireworks.
Nick Kyrgios posted this Instagram video of his recent serving session with former world No. 1 Naomi Osaka watching.
More: Steve Flink on Pete Sampras vs. Big 3 and GOAT Debate
The pair are friends and Yonex brand ambassadors.
Australian Open doubles champion Kyrgios had fun with a seemingly entranced Osaka in his Instagram post.
"Quick LA session with @naomiosaka," Kyrgis posted. "Analysing my serve to find any small detail… Her hunger to learn was pretty epic to see from a champ like her."
Photo credit: Mark Peterson/Corleve