Del Potro beat Bulgaria’s Grigor Dimitrov 6-4, 6-2 on Sunday to retain his Stockholm ATP title.
He thereby climbs to 14th in the race to the end-of-season ATP World Tour Finals in London while Dimitrov, who was top seed in Sweden, sits in fifth place.
The 29-year-old Argentine served nine aces and remained unbroken in a display of power to cruise past the Bulgarian in 1hr 25mins.
"I played the best match of the week against Grigor today," Del Potro said.
"It’s amazing to come back and hold this big trophy. And hopefully I can come next year as well."
After an injury-hit late season Del Potro made the Shanghai semi-finals last week before clinching his first title of the season on the indoor hard courts and the 20th of his career.
The Stockholm Open was first held in 1969 and has been played every year since.