Mertens broke for 2-1, 4-1 and 6-1 to take it 6-1.
Udvardy broke for 1-0 and again for 3-0 in a 6 minute game, surging to 4-0 before Mertens broke for 3-5 to narrow it, Udvardy holding for 6-4.
Mertens broke for 5-3 to seal it 6-3, with Udvardy holding for 2-2 in a deuce game the only standout moment in an otherwise routine set.