South Africa raced clear in the final quarter of the game to secure a 37-14 victory over France in the first Test at Loftus Versfeld on Saturday.
Scrumhalf Ross Cronje, and centres Jesse Kriel and Jan Serfontein, crossed for tries, while the home side were also awarded a penalty try.
France were in the game just before the hour-mark as they trailed by only two points after tries from centre Henry Chavancy and replacement scrumhalf Baptiste Serin, but could not contain the home team in the final 20 minutes.
It was a satisfactory outing for the Springboks, who are coming off the worst season in their history in 2016 when they lost eight of their 12 Tests.
France will likely be stronger next Saturday in the second Test in Durban having rested a number of their leading players. The final match in the series will be played in Johannesburg on June 24.
Jantjies kicked out on the full inside three minutes, and from the resultant line-up Franco Mostert went offside, giving Jules Plisson a chance to kick at goals from just inside the Springbok half, but his penalty drifted wide.
The Boks began to dominate territory and were handed the chance to take the lead when the French went offside and Jantjies slotted the penalty from right in front of the posts.
A sign of the home nerves came when they went straight back into the French 22 and won another penalty. With the visitors under the cosh, a kick to the corner might have been an appropriate call -- but instead captain Warren Whiteley called for the safety of three points and Jantjies obliged.
Jantjies' intelligent kick ahead and chase set up a lineout for the Boks 10 metres from the French line, but they lost the ball on their own throw and a promising attacking position was lost.
South Africa had 70 percent of the possession in the opening 20 minutes, but despite banging against the French defensive wall, they could not break through.
When the French finally got the ball, they took it through the phases to within five metres of the South African line, but with the home defence looking stretched, Plisson chose to kick across field when keeping the ball in hand was the better option, and the opportunity was lost.
A sniping break from loose-forward Siya Kolisi should have resulted in a home try, but after he offloaded to Ross Cronje, the scrumhalf ran towards the French defence and the Boks were eventually penalised for not releasing the ball.
The French wall was finally broken on 31 minutes as a scrappy turnover from the visitors just inside the Bok half saw the home side pick up possession.
They barged their way through the midfield, with Andries Coetzee breaking clear, and Kriel on hand to finish the move with a burst of pace. Jantjies added the conversion.
France struck back with a try four minutes later after a break and chip ahead by wing Yoann Huget. Coetzee inexplicably made no attempt to gather the ball as it bounced in the Bok goal area, and although Huget could not collect, Chavancy was on hand to dot down.
France went offside from the next Bok attack, giving Jantjies the chance to extend the lead again a minute before half-time, and his good day in front of the poles continued to hand the home team a 16-7 advantage at the break.
France won an attacking line-out five metres from the Bok line early in the second period, but the home defence managed to wrap them up and win a scrum with the ball buried under a pile of bodies, and the visitors were then penalised at the scrum.
But France did get the try to bring them back into the contest as replacement scrumhalf Serin darted over from close range after a ruck. Plisson converted and the home lead was just two points.
South Africa introduced experienced back Frans Steyn for Jesse Kriel at inside centre, his first test since 2012, and minutes later his grubber set up Courtnall Skosan in a race for the line.
The wing knocked on under pressure, but claimed that he was illegally held back by Brice Dulin and New Zealand referee Glen Jackson awarded a penalty try after asking the Television Match Official to make a decision. Dulin received a yellow card.
Home nerves were eased a minute later when Cronje went over for a try after sprinting clear following a well-worked home set-piece. A line-out was thrown long to captain Warren Whiteley, who fed his scrumhalf into a gaping hole in the French defence.
Francois Hougaard was the architect of a break for Coetzee that set up South Africa's fourth try as he burst clear and fed Serfontein to score.