Dawid Malan said he was gutted to again fail to convert a 50 into a century on Saturday and warned England must learn to convert good starts into big scores if they want to win Tests.

The England number three started day three of the second Ashes Test against Australia on one and built a strong partnership with skipper Joe Root.

But it fell apart after the first session when Root fell for 62 and Malan went for 80 in quick succession.

It was the second Test in a row that both men appeared headed for centuries but then threw their wickets away. Root made 89 in the first Test in Brisbane and Malan 82. 

"We talk about getting 20 wickets or what have you, but in Australia there's big runs to be had and big hundreds win you Test matches," Malan said after England were dismissed for 236 in their first innings in the Adelaide day-night match.

"In the last match both Rooty and myself were in a position to score hundreds and we didn't do it, and we were in the same position here and both times we've been found short as a batting unit compared to the Australian batting unit.

"So that's something we must do better from this next innings onwards, that if someone gets in, to make sure that we get that big 100."    

The 34-year-old South African-born Malan has now scored nine Test 50s but only converted one into a century.

Malan made his debut against South Africa in 2017 and played 14 Tests in 2017 and 2018, but did not play any more until being recalled against India in August this year.

He said he was "obviously pleased" to get runs in the opening two Tests but "to get to 80 in two innings in a row and get out softly is very disappointing".

"We've only had three innings so far, a couple of the boys have had some scores, but it's once we're in, it's about making the big scores," he added.

"Marnus (Labuschagne) did it this innings for Australia and Travis Head did it in Brisbane, and that's where the games slipped away a little and put us under pressure, and that's what we haven't done well enough so far."

Labuschagne smacked 103 in Australia's first innings in Adelaide while Head plundered 152 in Brisbane.