Adam Gilchrist has terrorised South African cricket fans in the last seven weeks with his explosive batting but the Australian vice-captain finally has good news for the Proteas.

They can wave him off at Johannesburg airport next week when Australia finishes its tour, thrilled that the most destructive force in international cricket is finally leaving their shores.

Gilchrist's reputation has boomed in South Africa - so far he's smashed 744 runs in all matches on this tour, including 105 from 104 balls last night as Australia claimed the one-day series with an eight-wicket win at Kingsmead.

But the Proteas won't have long before the wicketkeeper returns in 10 months for the World Cup defence in a nation starting to question the claims of its own team after a miserable summer against Australia.

The Proteas let Gilchrist sneak out of trouble again last night, dropping him twice and missing a run out before he hit top gear for his seventh one-day international century and his first in more than two years.

That drought is lost amid Gilchrist's flurry of Test runs, including 204 not out, 138 not out and 91 since arriving in South Africa.

But the 30-year-old knew he was due for a score in one-day matches.

"A lot of people may not have realised that but it was something I was churning over and I'm very satisfied to get that little monkey off my back," Gilchrist said.

"Not getting a hundred for two years was starting to play on my mind a little bit, as if I was letting the team down.

"That was the luckiest innings I've ever had up to 50 - I think I've seen luckier first 50s but I just can't remember them.

"After that I seemed to get things together and I was really happy with how I batted."

It was Gilchrist's first half-century in 11 one-day innings, pushing his career record to 4,144 runs at the remarkable strike-rate of 89.2 runs per 100 deliveries.

He reeled off 12 boundaries and a six over the mid-wicket fence from spinner Nicky Boje, who let out a cry of "catch" before realising he was talking to the fans in the seventh row.

Gilchrist's partnership with Matthew Hayden realised 170 runs - the highest opening stand in Australia-South Africa matches - establishing the left-handers as a sound combination following the sacking of Mark Waugh.

"It was pleasing to get control of (my innings) after a while and that's where Matty helps out. I've really enjoyed it every time on this trip," Gilchrist said.

"He talks a lot, he gets down out of the crease from the other end and has a good chat. It's very relaxing, the same way as batting with Junior (Waugh).

"Opening in the one-day game is where I like to bat and where I'm best suited for the balance of the side."

© 2002 AAP