KEY POINTS:
Veteran South Africa fullback Percy Montgomery believes his team's dramatic close encounter with Tonga could prove the perfect launchpad for a second World Cup crown.
The 1995 champions - who initially fielded a virtual second string side as coach Jake White rested or benched most of the side that inflicted a record World Cup defeat on England last week - were given an almighty scare by the unheralded Pacific Islanders in their 30-25 win that ensured top spot in Pool A and a likely quarter-final against Wales.
Tonga scored three tries to the Springboks' four and finished the breathless encounter battering the South African line as they sensed a shock victory.
"It was a wake-up call. It was good to have a test match like that. It brings you down a bit," said the 33-year-old Montgomery, who came on, with the bench's entire complement of back-ups, to turn the tide against a Tongan side ahead 10-7 early in the second half. "There's no way we will lose the momentum we have built up so far."
Montgomery, now the record Springboks' international caps holder, with 90 appearances, replaced the hapless Andre Pretorius who had missed four kicks at goal on an error-hit afternoon for a South Africa team with 11 changes to the side which beat England.
Montgomery, who went past Joost van der Westhuisen's record of 89 South Africa caps, is to join French club Perpignan but said he intended to keep playing at the top level after the World Cup.
"There's a lot of things to look forward to. I don't think I'll be retiring after the World Cup. I'll be keeping my options open."
White defended his decision to field his second string side despite them not having played competitively since they laboured to an 18-3 win over Irish province Connacht four weeks ago.
Once Tonga prop Kisi Pulu was driven over the line for a 10-7 lead, White summoned the heavy artillery from the bench in the shape of flying winger Bryan Habana, regular skipper John Smit, Brendon Botha, outstanding young centre Francois Steyn, Victor Matfield and Juan Smith.
Then Montgomery put Pretorius out of his misery and immediately landed a conversion of Juan Smith's try and an ice-cool penalty in the dying moments which left the heartbroken Tongans needing two scores if they were to achieve a famous win.
"My substitutes saved me and I'm very relieved," said White, whose side complete their pool matches against the United States next week before their likely last eight clash with Wales in Marseille on October 8.
"Everyone gets tested, that's why it's called a test match. In selection, we were tested to see whether or not those players could play in a World Cup.
"The important thing was that we passed the test, that's the key element and we have now won three out of three.
"We always knew the third game would be the tough one.
Tonga beat Samoa last week but the plan was always to give some guys an opportunity otherwise we could have had the same guys possibly playing seven weekends in a row."
"We had opportunities when we dropped the ball, missed a few kicks at the posts and missed touch.
"The boys didn't play well against Connacht but we are glad we tried that experiment. We have learned from that. I'm not going to have them shot at dawn."
- AFP