Unseeded 20-year-old Nagal defeated his British opponent 6-3 3-6 6-2 in the summit clash of the USD 100,000 hard court event, earning crucial 100 ATP ranking points.
Nagal, who is ranked 321, is likely to gain more than 80 places on the ATP ranking list when the new rankings will be issued on Monday.
The effort won Nagal a decent prize purse of USD 14,400 and more importantly he will now be ranked close to 225 which will be his career-best rank.
India hosted only two Challenger level events this year and both were won by home players. Bhambri had won the USD 50,000 Pune Challenger last week.