The two-time world champion, who took bronze at the Summer Olympics in 2012, downed Ekaterina Dyachenko in the semis before proving too strong for Egorian in the showpiece match.
The 24-year-old looked in great shape and eventually prevailed 15-10, giving her a major boost ahead of the European Championships which get underway in Switzerland on June 5.
President Petro Poroshenko greeted Kharlan in his Twitter post. "Vivat Olha Kharlan! Congratulations on the winning at the Moscow Grand Prix! All the country wins with you. Glory to Ukraine!" the president wrote.