Stuart Broad's England team-mates are starting to mention him in the same breath as Test great Glenn McGrath.

After Broad's three wickets for one run in 15 balls on Tuesday, England were on the brink of victory on Wednesday morning against a South Africa team reduced to 76 for six and still 156 runs from avoiding an innings defeat.

The hosts' chances of making four wickets last through the final day of the second Test are slim.

Broad bowls England to brink of victory

But irrespective of whether England go 1-0 up with two matches to play, Ian Bell has started the comparisons between 23-year-old Broad and Australian McGrath, who finished his career with 563 Test wickets.

"With his height and the lengths he bowls, he is going to be tricky for any batsman," said Bell, who made 141 in England's 575 for nine declared.

"Facing Glenn McGrath, a tall guy who can always hit those good areas, it is always hard and Stuart asks those questions all the time."

Broad (three for 18) took his wickets immediately after tea and was on a hat-trick at one stage after Graeme Swann (three for 22) had started the South Africa slide.

"That was the great thing about that spell. It's the hardest place for a batter to answer questions, when the ball is always around the top of off (stump)," added Bell.

"It just started reversing there, which I think was the key to those wickets.

"Whether the three guys (who were out to Broad) knew that, I don't know. We didn't expect it either, with the drizzle."

Proteas staring at defeat in Durban

Bell conceded, meanwhile, that South Africa fast bowler Dale Steyn's description of his ninth Test century - and first for 17 months - as "career-saving" was accurate.

"After (the first Test at) Supersport Park there was a lot of talk from many people that it could have been his last innings in South Africa," said Steyn.

"He has come out and batted extremely well on a good wicket. He's a good player. Anyone who plays for their national side is a good player and England have done well to back him rather than drop him and throw someone else in."

Reflecting on his own team's collapse - they lost five wickets for 13 runs to be 50 for six at one stage - number 10 Steyn recalled: "I was in the shower and when I got out I had to put my pads on. There isn't time to get angry.

"I've been in sides where I have been fortunate enough to have a team six down like that, we were on the receiving end this time."