South Africa legends Schalk Burger and Victor Matfield hailed loose forward Duane Vermeulen after edging hosts France 29-28 in a Rugby World Cup quarter-final thriller at the weekend.
Vermeulen, 37, who will retire after the global showpiece, was substituted early in the second half only to return when fellow back-rower Pieter-Steph du Toit required a concussion test.
"His impact on the closing 20 minutes was massive," Burger, a flanker in the team that beat England in the 2007 World Cup final in Paris, told the SuperSport channel.
"When Siya (Kolisi) left the field, Bongi (Mbonambi) took over as captain and he wears his heart on his sleeve. He was at the coalface, battling to establish forward supremacy.
"Duane is more experienced as a leader and, working alongside Bongi, introduced calmness and clarity and provided some crucial information to the team.
"The pressure was intense, with France six points ahead and just 15 minutes remaining, and the influence of Duane cannot be understated," added Burger.
Matfield, who formed a famed lock partnership with Bakkies Botha for many seasons after the 2007 World Cup triumph, backed Burger in his assessment of Vermeulen.
"The Springboks were rushing things a little bit at times entering the final quarter, and that was a serious concern.
"Duane brought calmness to the team, passing crucial advice to different players and assisting Bongi with the leadership.
"It was a team effort, but the role of Duane was absolutely critical. His experience from many seasons of Test rugby shone through in those tense final minutes."
- Puzzled -
Burger admitted he was puzzled by the Springboks' triumph, which set up a last-four showdown with England in Paris on Saturday. It is a repeat of the 2019 final won 32-12 by South Africa.
"It was a great escape for us. France dominated territory and possession, forced South Africa to make more than 160 tackles, and bossed the gainline battle.
"Where the Springboks did impress was the ability to absorb continuous pressure, then strike decisively in counterattacks."
Burger and Matfield also praised winger Cheslin Kolbe, one of the four Springbok try scorers, who moved to Japan last season after stints with French Top 14 outfits Toulon and Toulouse.
"His workrate and desire was amazing," said Burger. "You cannot coach desire -- you either have it or you do not."
Matfield called the successful sprint by Kolbe to block a Thomas Ramos conversion attempt "incredible. I cannot immediately recall the last time I saw that happen".
Capped 127 times by South Africa, Matfield said character under pressure enabled the Springboks to survive a French barrage for much of the match.
"We were under the cosh, but experience born out of many tight finishes in Tests came through to keep alive our hopes of back-to-back titles."
The winners between three-time world champions South Africa and England will face New Zealand or Argentina, who meet on Friday, in the October 28 final.
dl/pi