Ramkumar, ranked 228, prevailed over the Russian 3-6 6-3 6-2 in his semifinal.
China's Quyang, ranked as low as 791, prevented an all-Indian final by getting the better of second seed N Vijay Sundar Prashanth 6-2 5-7 6-4.
Meanwhile, the top seeded Chinese duo of Xin Gao and Ouyang lifted the doubles title with a 2-6 6-3 10-5 win over second seeds Mohit Mayur Jayaprakash and Vijay Sundar Prashanth in the final.
The rivals were matching each other in terms of holding their service games to 5-all but Prashanth was classic in winning the rallies in the 11th game to break Bowen and then held his serve for the set.
In the decider at 4-4, Bowen broke the Indian in the ninth game and then held his own for the match.
In the second set, the Indian rarely yielded space to the Russian and broke his rival in the sixth game and then went on to neutralize the set score.
The third set was a delight as the top seeded Indian rose to a 4-0 lead that upset the rhythm of Marcos, who was hauled up for technical fault when holding the 'advantage' in the 5th game and won the point. The Russian also had three minutes time out for medical reasons but Ramkumar remained focused to win the set and the match.
