Man stabbed with screwdriver after group gatecrashes house party It took two "idiots" to ruin an 18th birthday for around 90 party-goers celebrating at an Erskineville home on Friday night. But the parents of the teenager celebrating his birthday denied police reports that it was a gatecrasher who allegedly punched a 17-year-old boy in the face, instead saying it was someone on the guest list who had delivered the blow. "It was just the case of two idiots," the father, who did not want to be named, said. The party had been going well until then, but as soon as the incident happened, just after midnight, the police were called and that was it. It certainly put a dampener on the whole night. Police reported a man unknown to the teenager celebrating his birthday or his parents entered their Rochford Street home, went into the lounge room and punched a 17-year-old boy in the face. He also allegedly had a bottle thrown at his head before the perpetrator fled. Paramedics took him to hospital, where he was treated for minor injuries. But the father denied the guest was unknown, saying they had taken every precaution to ensure no unwanted guests were allowed inside. "We had a guest list, we had hired security, there were no gatecrashers," he said. The teenager celebrating his birthday was "pretty stressed" but okay, his mother said. It was one of two incidents on Friday night that could have ended much more tragically, with the second - in Minchinbury, caused by a group of gatecrashers. A brawl broke out, with people spilling onto the street, when the gatecrashers showed up at a party of 70 people at Minchin Drive, and spoke to a 17-year-old girl who lived there. When a 23-year-old man tried to intervene and help a man who had fallen to the ground, he was repeatedly stabbed with a screwdriver in his eye, arms and chest, suffering a punctured lung. As he fell to the ground he was kicked and assaulted. An ambulance was called and he was taken to Westmead Hospital in a stable condition. One teenager at the party said on social media that the 17-year-old had been celebrating her upcoming 18th birthday and that her parents were home at the time. An 80-year-old woman living nearby, who did not wish to be named, said there were frequent loud parties in the street. "My husband said he heard the kids yelling and carrying on last night," she said. It's quite scary - you don't want to go outside. Police have asked anyone with information to call Crime Stoppers on 1800 333 000.