Chela and Schwank defeated the Kazak team of Evgeny Korolev and Yuriy Schukin 6-3, 6-2, 7-5 for a 3-0 Argentina lead in the best-of-five series.
Juan Monaco and Juan Martin del Potro posted straight-set singles victories Thursday to put Argentina within one win of advancing to the semifinals.
The Argentines will next go against Serbia of Sweden, who played their quarterfinal series this week, Sept. 16-18.
Chela and Schwank collected six service breaks, including three in the third set. They fought off six break points in the first set and didn't face any in the second. Korolev and Schukin managed a pair of third-set breaks but the Argentines answered each time.
Chela and Schwank won 57 percent of the points, including 48 percent when receiving serve.