South Africa captain Siya Kolisi has issued a heartfelt apology to supporters after his side's "unacceptable" defeat to Australia in the opening match of The Rugby Championship . The Springboks raced into a commanding 22-0 lead inside the opening quarter at Ellis Park on Saturday, but completely collapsed as the Wallabies mounted a remarkable comeback to claim a historic 38-22 win and leave the hosts stunned. Not only was it a first win for Joe Schmidt's side at Ellis Park since 1963, it was also their first win anywhere in South Africa for 14 years. Sign up to Inside Welsh rugby on Substack to get exclusive news stories and insight from behind the scenes in Welsh rugby. The shock defeat left head coach Rassie Erasmus furious, as he confessed to reporters after the match that he was "embarrassed" having watched his side be "tactically out-smarted" and "physically dominated" by Schmidt's men. Skipper Kolisi has also addressed his side's "unacceptable" performance in the wake of the shock result, telling SuperSport that he and his team-mates only have themselves to blame. “We let ourselves down today,” said the 34-year-old back rower. "The things we worked on – discipline, the breakdown – they definitely won the breakdown battles. We didn’t put them under enough pressure. "We let ourselves down a lot and we have to take that on the chin. It’s unacceptable the way we performed. You can’t start like that, then take your foot off the pedal. That’s just unacceptable from us. “It was the errors, but also the breakdown," he added. "We’d fight, get into the 22, and then they’d steal the ball. It’s something we knew they would do, because they’ve been good at it. We just didn’t look after the ball well enough.” Kolisi, who was making his first Test start at No.8, went on to praise the Wallabies for their performance before apologising to the home fans for what they had just witnessed. “They played really well," he continued. "Credit to the Australian team – they kept on fighting, they never gave up even though we started well and went ahead. So well done to them. But from us, you can see from the boys we’re not proud of the performance we put out today. “We’re not going to drop our heads. We’ll go again next week and fight. Whoever gets the opportunity to play, we’re going to take it. There’s not much else we can do now but fight. “Thank you to everybody who supported us. Sorry about the performance, but we’ll come again next week.” The Springbok legend's words came as his head coach Erasmus was turning the air blue in his post-match press conference with an even more frank assessment of his side's performance, which he described as "dog s***". "I must be honest, it is probably one of the most embarrassing press conferences I've done in a while," he said. "Not because we were awful, they were really good and I want to put the old cliché out there, credit to them, they were good - but we made them better with our poor performance. "To be 22-0 up, we did the same against Italy, 27-3 up and then we let teams back in. Yes, we gave them one or two soft tries but overall they were just better than us on the day in most departments and yeah, we as coaches got it terribly wrong, and we have to look first at ourselves before we point fingers at the players." Erasmus added: "We know that from now to next Saturday we have to take a lot of flak and we're very disappointed, we feel bad for our supporters and are feeling bad for our players overall for what we produced. "I don't think they tactically out-smarted us, I think they also physically dominated us. The saddest thing is we didn't even fight back to take a bonus point away. Listen man, I can butter this up to sound cool and respectful, but we were really dog s*** on the day."