Pankration is an ancient martial art which mixes wrestling and boxing. The sport can be traced as far back as the second millennium BCE in the territory of ancient Greece.
In Pankration, which is over 2500 years old, fighters were allowed to throw kicks, the exact technique of how they through them we do not know, but historical literature does describe a front kick to the midsection as being a popular strike.
Pankration probably resembled Muay Thai or modern K-1 fighting.
How exactly fighters held their hands is not known either, Pankration gloves were more similar to beefed up MMA gloves. They protected the knuckles and wrist, but the palms were open and enabled you to grab your opponent.
For ancient fighters, their training is described as being drill based much of the time. Modern combat sports athletes, take a note.