Wingers Courtnall Skosan and Raymond Rhule scored their first Test tries as South Africa stretched a winning run to four Tests by defeating Argentina 37-15 Saturday in the Rugby Championship. Springboks fly-half Elton Jantjies kicked 17 points at Nelson Mandela Bay Stadium in Port Elizabeth as the home team finished comfortable victors after leading 13-5 at half-time. The victory followed a 3-0 whitewash of France two months ago and continued a turnaround after a calendar-year record eight defeats in 12 Tests last season. Argentina were virtually always on the back foot, committing countless handling errors, conceding numerous penalties and fly-half Nicolas Sanchez had an off-day with his goal kicking. Relentless early pressure from South Africa finally paid off after 12 minutes when Jantjies slotted a penalty after flanker Tomas Lezana went off his feet at a ruck. Jantjies doubled the lead on 20 minutes from another penalty with Lezana again the offender, this time caught offside by French referee Romain Poite. A six-point lead after 20 minutes was hardly the reward the Springboks deserved as they had kept the Pumas hemmed deep in their half on a cool, clear eastern Cape evening. It took Argentina 27 minutes to reach the South African "22" and almost immediately Sanchez had a chance to score, but missed a kickable penalty attempt. However, five minutes later the South Americans did score when a grubber kick from centre Jan Serfontein was snapped up by full-back Joaquin Tuculet, who counterattacked. Winger Emiliano Boffelli carried forward the move and his clever kick ahead was snapped up by scrum-half Martin Landajo and he dotted down in the corner. Sanchez failed to convert, leaving South Africa with a 6-5 ahead that did not reflect their possession and territory dominance. South Africa finally scored a try after 37 minutes as Skosan collected an inside pass from Jantjies, shrugged off a tackle and went over between the posts. Jantjies converted and South Africa left the field at half time full value for a 13-5 advantage. Sanchez and Jantjies exchanged second-half penalties before Rhule burst between two Pumas to score his first try, which was converted. Slick handling sent Boffelli over at the other end and substitute fly-half Juan Martin Hernandez converted to leave the South Americans trailing 23-15 with an hour gone. South Africa controlled the final quarter and forwards Siya Kolisi and substitute Pieter-Steph du Toit scored tries which Jantjies converted.