Fognini had been 0-2 in career finals appearance before beating Philipp Kohlschreiber in three sets last week at the Mercedes Cup in Stuttgart He followed that with a 4-6, 7-6 (10-8), 6-2 decision over Delbonis in Sunday's final in Hamburg.
Delbonis had a superior week en route to the finals, earning a spot in the main draw through qualifying and beating two seeded players to get to his first ATP final. The run included Saturday's 7-6 (9-7), 7-6 (7-4) stunner over world No. 5 Roger Federer.
His magic continued through the first half of the match Sunday, posting a 10th-game break to take the first set and rebounding from an early break in the second.
He was up 4-1 in the second set when Fognini started his comeback with a break that allowed him to get back to even in the set. Delbonis had three match points in the tiebreaker but Fognini had the answer each time and finally won the set.
That seemed to take the much of the battle out of Delbonis and Fognini used a second-game break to take the third-set advantage and, despite suffering a late break, easily put the match away after that.
Fognini earned $330,000 along with the championship giving him more than $3.6 million won in his 10-year professional career. The runner-up check of more than $150,000 gives Delbonis a lifetime earnings total of $575,000.
The formal name of the tournament is the best-at-home Open-German Tennis Championships.