By Scott Heinrich BBC Sport Online

When Mike Atherton announced his retirement in the summer of 2001, Michael Vaughan was still an international novice.

A handful of Test appearances to that point marked him as a potential replacement for Atherton, but he had plenty left to prove.

Vaughan has played 12 Tests since the former England captain called time, and that is all he has needed to make the opening slot his own.

His century in Adelaide was his fifth in 14 innings, leaving no doubt that in Vaughan, England have an opener of true quality.

See Vaughan's innings in pictures

Indeed, speaking in last month's Wisden Cricket Monthly, Atherton questioned the longevity of his own career in light of Vaughan's emergence.

Atherton retired with a Test average of 37.7

"Vaughan and Marcus Trescothick look a fine partnership; indeed, the regal way Vaughan batted all summer makes me think I might have gone on too long."

And writing in his autobiography, Atherton was again brimming with praise.

"He is a Mancunian and a solid citizen - head high, feet moving forward and back according to length, a high elbow the fulcrum of his play, orthodox and stylish, a seamless transition."

Vaughan's sublime 177 on day one of the second Test was just the tonic for England in their time of need.

But more than that, it showed that he has not stopped progressing since the summer when he scored four Test centuries against India and Sri Lanka.

Vaughan is not afraid to play his shots

Never mind the catch that never was early in his innings; every batsman needs a slice of luck from time to time and Vaughan cashed in on his.

Past Yorkshire greats have enjoyed themselves in Adelaide - Len Hutton and Geoff Boycott both made Test centuries there.

Vaughan is a fitting heir to their legacy.

After looking a carbon copy of the obstinate, durable Atherton in his first few Test outings, Vaughan is now creating a mould of his own.

Vigilance

The vigilance that marks any top opener is still evident, but as Vaughan has matured at Test level, so has the expansiveness of his strokeplay.

In many ways, he is becoming the quintesesstial modern-day Test opener.

His scoring rate - 53 runs for every 100 balls faced - is vastly superior to that of Atherton, whose mark was 37.

Vaughan was struck on the shoulder by Gillespie

And his Test average is already much better than Atherton's at 49.23, although the challenge now is to sustain it at that level.

But there are characteristics apparent in Vaughan that statistics cannot measure.

As it was in Atherton, the appetite for a fight is very much alive in Vaughan.

Atherton's battle of wills with South African paceman Allan Donald at Trent Bridge in 1998 was unforgettable.

And seeing Vaughan shrug off a Jason Gillespie bouncer which struck him on the shoulder in Adelaide evoked similar sensations.

Vaughan's disappointment at being dismissed by the last ball of the day was palpable, and critics will point to yet another double ton squandered having passed 190 twice during the summer.

But such carping is unlikely to bother Vaughan: England's new lion at the top of the order.