Bermuda's world champion Flora Duffy earlier won the women's race to clinch the first gold of the Games.
Duffy's gold was the first for her country at the Commonwealth Games since Clarence Saunders won the men's high jump in 1990 in Auckland, where triathlon made its debut as a demonstration sport.
Schoeman, who won bronze at the 2016 Rio Olympics, celebrated for all of the finishing straight and high-fived a team mate running the opposite way, to clinch the sprint-distance event ahead of Australia's Jake Birtwhistle and Scotland's Marc Austin.
England's Jonny Brownlee, the silver medallist in Glasgow four years ago and at the Rio Olympics, finished seventh, while two-time Olympic champion Alistair was 10th.
The Brownlees had led a breakaway pack of six on the 20km cycle leg, but then immediately dropped away out of transition into the run with Schoeman and New Zealand's Tayler Reid establishing a large gap.
Schoeman, however, put the hammer down to not only drop Reid within the first 400m of the 5km run but also pulled away from the rest of the field.
He took a 14-second lead into the final 2.5km lap and slowed as he ran the last 200 metres, with Birtwhistle finishing fast to become the host nation's first medallist of the Games.
"It was a tough race, the swim was rough," Schoeman told reporters. "My legs were exhausted at the start (of the run) but I gave it a surge and kept up the momentum, I just had to stay cool and save energy.
"I just kept thinking 'don't give up, anything can happen' (and) that last 50 metres felt amazing."
FIRST GOLD
Flora Duffy. Source: Getty
The tiny Caribbean nation of Bermuda had won just five other medals at the Games before Duffy ran away from England's Jessica Learmonth after the pair had been locked together for the swim and cycle legs of the race.
"I am from a tiny country with not a lot of medallists so I am expected to win," Duffy told reporters of the pressure she feels at home after winning successive triathlon world championships in 2016-17.
"I came in the favourite so that adds its own pressure. For me it was personal, I wanted to do well."
Canada's Joanna Brown took bronze, which she said was a massive confidence boost after she fractured her shoulder following a fall from her bike last month in Abu Dhabi that restricted her swimming and cycling training.
"Coming onto the bike I was a bit nervous," Brown said. "I haven't done much road training.
"I have been doing a lot of running training so I knew that was going to be my strongest leg so I just ramped it up there. I really wanted it, so I'm super happy with the result."
The best placed Australian was Ashleigh Gentle who finished fifth after dropping off the pace set by the chase group. Gillian Backhouse finished ninth and Charlotte McShane 11th.
