At one point, NASA was planning to launch the first Mars Sample Return mission using this mission scenario. In this early artist concept, a rover has delivered the samples back to the small rocket carried by the lander. Known as the MAV or Mars Ascent Vehicle, it would carry the samples up to Mars orbit. At that point, it was expected to rendezvous automatically with a French CNES Orbiter which would fly the samples to Earth. A technically difficult feat to accomplish, I'd say!

That scenario is not the current plan. It may yet be resurrected, though, with a US orbiter possibly.