Marcus Harris looked every bit the international batsman on Friday as he posted his maiden Test half-century and impressed not only the Perth Stadium crowd but his teammates to boot.

Harris compiled a polished 70 from 141 balls and sent 10 deliveries to the rope after captain Tim Paine won the toss and elected to bat on a green wicket that proved a handful for the batsmen.

The 26-year-old made encouraging starts in his debut Test in Adelaide, posting 26 in each innings but failed to build on the solid foundations he carefully spent constructing.

He was back on the tools in Perth as he soaked up 15 balls before clipping a single to get off the mark from the 16th delivery he faced.

After finally troubling the scorers, he hit three boundaries in the seventh over off towering quick Ishant Sharma, the pick of the bunch a scrumptious straight drive.

His stroke play off the front foot was the highlight of his innings, which was ultimately terminated by a horror delivery from off-spinner allrounder Hanuma Vihari that sharply bounced and took the shoulder of his bat to first slip.

Aaron Finch had the best seat in the house to watch Harris's innings, standing at the non-striker's end as the pair put on 112 for the first wicket.

Finch was impressed with how Harris, who joked on Wednesday how he is unfazed by the comparisons with David Warner, Justin Langer and Chris Rogers, used his cool composure to conquer the sweltering temperatures and combat the challenging conditions.

"What everyone's seen from his so far in the media that he's done, not a real lot fazes him," Finch said with a smirk after play on Friday.

"He's a pretty chilled out character who just goes with the flow and that's the way he's always been, he hasn't changed for a long time, he's a great guy.

"But I think the tightness of his technique, (how he) covers his off-stump, looks to hit down the ground and for such a short guy that can be unique at times.

"He's definitely got all the shots, but I think the way that he adapts his game and his game plan depending on the wicket, depending on the attack, that will hold him in great stead going forward.

"We saw a glimpse of it today and it was pretty impressive."