The home side trail the tourists by 36 runs in their second innings with seven wickets remaining after they were bowled out for a paltry 55 in the morning session.
They went to the close on 62 for three in their second innings, having earlier dismissed India for 153 on a record-breaking opening day in Cape Town.
"I would take 100 (victory target) all day," Elgar told reporters. "When our bowlers click they can rip through any batting lineup and on this wicket that is possible."
Elgar was out for four and 12 in his final test before retirement, having won the toss and elected to bat on what he knew would be a tricky surface.
"I didn’t know it would play in that way though, with the naked eye it did not look so bad," he said. "But it’s one of those wickets where if you knuckle down, you never know what can happen.
"You still have to put the ball in the right area and they (India) executed that to a tee. This pitch just seemed to get quicker as the (first) session went on. I don’t know what to make of it."
India had been 153 for four in their first innings before losing their last six wickets for the addition of no runs, the first time that has happened in 147 years of test cricket.
"The older ball was still doing something. We’ve just experienced a really crazy day of test cricket," Elgar said.
He praised his players for not letting their heads drop after they were skittled for their lowest score since 1932.
"I just said to the guys I will measure them on attitude and execution with the ball. We maybe leaked a few runs with half-volleys but I can’t fault the bowlers for the effort they put in."
Asked if he would change his decision to bat first, Elgar suggested batting last against any sort of three-figure target would be a real challenge.
"I would still stick to batting first after seeing how the wicket has played," he said.
