(Note language some may find offensive in paragraph eight)
By Greg Stutchbury
TOKYO, Oct 21 (Reuters) - For all of South Africa's physical dominance of Japan in their Rugby World Cup quarter-final on Sunday, the Springboks are aware that they were lucky to get away with a 26-3 win after they squandered several point-scoring opportunities.
Rassie Erasmus's side face Wales in a semi-final next Sunday in Yokohama where they are unlikely to get as many chances against the Six Nations champions.
"We must find those pressure points ... (and) when we get the opportunity, we must utilise them," Erasmus said after his side wasted three or four chances to put their quarter-final beyond doubt by halftime. "Then we have a chance."
The Springboks have not advanced to the World Cup final since they lifted the Webb Ellis trophy in Paris in 2007, and at times in the first half they were scrambling against a fast-paced Japanese side in the cool Tokyo conditions.
The key to their victory, however, was laid in that troubled first half when the much bigger Springboks hurt the Japanese in the collisions.
In previous matches the home side were able to get quickly to their feet, but on Sunday it was noticeable how many stayed down or rose slowly, holding their ribs, shoulders and lower backs due to the impact of the collisions.
By the second half the Japanese side looked like the walking wounded. While they never gave up, the Springboks ground them down and scrumhalf Faf de Klerk's try following a 30-metre-plus rolling maul sent an emphatic message.
"South Africa were just too physical. They just bashed the shit out of us," Japan winger Lomano Lemeki said.
"You can't use all your energy if you're the smaller team trying to stop the big guys. We knew they were going to come out and try to bully us. We just couldn't adapt to what they did."
Lemeki said they had used their speed and managed to breach South Africa's defensive line, but the Springboks scrambled well and Erasmus said he was happy with the way his team were playing.
"I know a lot of people see a few holes in our defence, but we trust our system," Erasmus said.
"We know defence is a pretty important thing if you want to win the World Cup. We have good confidence in our defence system."
Wales are unlikely to provide the same sort of challenge in terms of their speed on Sunday. But they also have a strong defence, only conceding 69 points in their four games in Pool D, which included Australia and Fiji.
They will also be better-suited to face the Springboks up front, and discipline will therefore be paramount, according to de Klerk.
"If we can keep our discipline down to at least six penalties or less, that's going to be a big thing for us," he said.
"It's going to be a tight game." (Reporting by Greg Stutchbury; Editing by Hugh Lawson)