Ranked 368, Sanam ousted the American world number 97, 6-0, 6-3 in the second round of the $50,000 hard court event.
At Challenger level, Sanam has not gone beyond quarter-finals this season. At Binghamton event in the US, Sanam had lost to Bradley Klahn.
He now faces Canadian Peter Polansky, to whom he had lost in the ITF Futures final in Canada in September this season.
Polansky will be a tough nut to crack as the Canadian is in good form. He has already shocked third seed and world number 94 Jack Sock in the opening round.
Image: Sanam Singh
Photograph: Feng Li/Getty Images
Rankings: Yuki up to 204 in singles; Paes in 9th spot in doubles
Mixed results for India at ATP Challenger events
ATP Challenger: Yuki in semis, Somdev and Myneni in quarters
Challenger Tour: Yuki in final of the Traralgon event
Yuki enters quarter-finals of Traralgon Challenger