The Lions enter Saturday’s second Test at Cape Town Stadium in a position of strength after edging a tense opener 22-17 as they pursue equal footing with the famed tours of 1974 and 1997.
But Henshaw recalls from Ireland’s visit to South Africa in 2016 that the Springboks are highly resilient and he is expecting a ferocious response by opponents fighting to save their series.
“Everyone knows we are in such a great position at the moment and it’s in our hands to go out and back it up,” the Leinster centre said.
“It’s going to be very tough but it would be unbelievable to have it wrapped up in two games.
“South Africa are going to be emotionally driven. After the last game, they were saying that when their backs are to the wall, they’re a dangerous team.
“I know that personally from playing here with Ireland in 2016, when we beat them in the first Test and they came back and managed to overturn us to win the series.
“They are massively dangerous and they are going to be well up for it. We need to be ready to match their power and the fire they’re going to bring.
“We are expecting them to come out of the blocks fast and to throw everything at us.”
South Africa led 12-3 at half-time of the first Test but fell away after the interval in the face of a spirited Lions fightback.
“There’s a huge onus on us to go out there and back it up. We know that last weekend wasn’t perfect in any sense. It was a real arm-wrestle,” Henshaw said.
“They won the first half and we came back and overturned them but there’s definitely room for improvement on our side.
“We’ll be looking to execute and take our chances when they come and keep the pressure on them. We have to bring the level of our performance up again.”