Blewett finished with 214, the highest Test score made at The Wanderers, and Waugh 160 as Australia piled on the runs before declaring at 628 for 8, a first-innings lead of 326.
Shane Warne then stepped in with two wickets to leave South African hopes of saving the game in tatters as they struggled to 99 for 4 by the close. That left them 227 runs behind with their last pair of specialist batsmen at the crease, Jacques Kallis unbeaten on 29 and Jonty Rhodes on three.
Gary Kirsten dragged a wide ball from Shane Warne on to his stumps when he had made eight and then Steve Waugh hit the stumps to run out the other opener, Andrew Hudson, for 31. It became 46 for 3 when Daryll Cullinan was caught behind off Warne for a duck.
Hansie Cronje and Kallis temporarily halted the slide, sharing a fourth- wicket stand of 44, but the introduction of Steve Waugh's medium pace broke the partnership. Cronje flicked at a wide leg-side delivery and was caught behind the wicket by Ian Healy for 22.
Earlier, Waugh and Greg Blewett had effectively batted South Africa out of the game with their fifth-wicket partnership as Australia resumed on 479 for 4 after the pair had batted throughout the third day.
Waugh was finally caught behind just before lunch for 160 from 366 balls in 501 minutes with 22 fours. His 12th Test century was also his seventh score in excess of 150.
Blewett's innings beat the previous best at this ground, Mike Atherton's unbeaten 185 two years ago. When Blewett was eventually caught off the back of the bat by Paul Adams at third man, he had made 214 in 519 minutes from 421 balls and hit 34 boundaries.
The partnership was the highest against South Africa in Tests, beating the 370 for the third wicket by the English pair of Bill Edrich and Denis Compton at Lord's in 1947.
The previous highest Australian partnership for any wicket against South Africa was 275 for the fifth wicket by Colin McDonald and Lindsay Hassett in Adelaide in 1952-53.
Fourth day, South Africa won toss
SOUTH AFRICA - First innings 302 ( W J Cronje 76, D J Richardson 72no).
AUSTRALIA - First innings
S R Waugh c Richardson b Kallis 160
G S Blewett c Adams b Klusener 214
M G Bevan not out 37
I A Healy c Kirsten b Adams 11
S K Warne b Cronje 9
Extras (b1 lb15, nb10, w4) 30
Total (for 8 dec) 628
Fall (cont): 5-559 6-577 7-613 8-628.
Did not bat: J N Gillespie, G D McGrath.
Bowling: Donald 35-7-136-2 (nb1, w2); Pollock 32-3-105-2 (nb8); Klusener 37-10-122-1 (nb1); Kallis 21-4-54-1 (w2); Adams 52-7-163-1; Cronje 16.4- 5-32-1.
SOUTH AFRICA - Second innings
A C Hudson run out 31
G Kirsten b Warne 8
J H Kallis not out 29
D J Cullinan c Healy b Warne 0
*W J Cronje c Healy b S R Waugh 22
J N Rhodes not out 3
Extras (b4 lb2 6
Total (for 4) 99
To bat: S M Pollock, L Klusener, D J Richardson, A A Donald, P R Adams.
Fall: 1-36 2-41 3-46 4-90.
Bowling: McGrath 10-5-17-0; Gillespie 11-4-24-0; Warne 18-9-32-2; Bevan 5-0-16-0; S R Waugh 4-1-4-1.
Umpires: C J Mitchley (SA) and S Venkataraghavan (Ind).Reuse content