Murray produced a clinical display to brush aside the Portuguese 6-2 6-2 6-4 to set up a last-32 encounter with Ricardas Berankis.
And with the temperatures in Melbourne topping 100 degrees Fahrenheit, Murray was pleased to be given a chance to conserve energy.
"It doesn't matter how much training you do, it's tough in these conditions," he said.
"It's extremely hot, especially when the sun comes through the clouds. It's good to get it done in three sets.
"The longer the rallies go the tougher it becomes on the legs.
"You need to get in control of the points and dictate them because otherwise you will get very tired very quickly."