ATLANTA — Julian Gressel tied it in the 56th minute and Atlanta United held on for a 1-1 draw with the Portland Timbers on Sunday. A loose ball deflection off defender Larrys Mabiala bounced into Gressel’s path and he pounced on it with a right-footed volley. Atlanta (10-3-4) stayed atop the MLS standings and extended its unbeaten streak to five games. Mabiala opened the scoring in the 32nd minute.