After comfortably winning the first set, the 25-year-old went down in the second before he rebounded strongly to clinch a 6-4, 4-6, 6-4 win over Schnur in the final match on Sunday evening.
Yesterday, Canadian Denis Shapovalov defeated Ramkumar Ramanathan 6-3 ,7-6(1), 6-3 in a must-win match to shut the doors for the visitors.
The onus to keep India alive was on 22-year-old Ramanathan, but his failure to convert chances meant that the country will yet again strive in the Asia/Oceania Group I in the 2018 season.
It is fourth straight year that India have not managed to cross the World Group Play-offs hurdle, having earlier slumped to a defeat against Serbia, Czech Republic and Spain in three attempts. Canada, who had lost to Great Britain in the first round in February, go back to elite 16-nation World Group.