Del Potro, who triumphed in the US Open back in 2009, has enjoyed a very welcome renaissance this year, after a series of wrist injuries that pushed him to the brink of retirement.
Having claimed a silver medal at the Rio Olympics and helped Argentina to the Davis Cup final, Del Potro now found himself in a first Tour final since he won in Sydney in January 2014.
And the World No 63 needed just under an hour and 20 minutes to defeat his American opponent, securing the crucial break in the 11th game of the opening set.