The 20-year-old clocked 10.41 seconds to lower the previous Jersey record of 10.48 seconds, which was set by his teammate Steven Mackay last year.
Oldham finished second in his heat behind Ghana’s Benjamin Azamati, who won the race in an impressive 10.00 seconds. Although his time was not enough to secure a place in the semi-finals, the young sprinter described the achievement as a major personal milestone.
“I was coming in a bit dodgy, I’d been a bit sick, so I wasn’t expecting too much,” Oldham told BBC Jersey.
“But to come and do it on the big stage I’m really proud of myself.”
Reflecting on his race, Oldham said his strong start from the blocks gave him confidence during the sprint.
“I shot out of the blocks,” he said.
“I was expecting the guy on my outside to shoot past, but when I noticed I’d got out before him I was like ‘I just need to hold form’ and I managed to do it.”
Record achievement boosts confidence ahead of 200m event
Oldham is one of three Jersey sprinters competing at the Games, marking the first time the island has fielded a full contingent in the men’s 100m.
The trio will return to action in the heats of the 200m on Wednesday, an event Oldham approaches with increased confidence after producing the best performance of his career.
“I feel like I did my coaches and my friends and my family proud, it really does mean a lot to me,” said Oldham, who finished as the 30th-fastest athlete in the 100m heats, with only the top 17 advancing to the semi-finals.
“I’ve got more to come on Wednesday as well, so I’ll have to see what I can do there.”
Oldham said his recent form in the longer sprint had given him belief that he could produce a strong showing in the 100m.
“I was quietly confident in 100 (metres) because I’d got a personal best in the 200, so I thought I’d have a chance to get better,” he said.
“But I didn’t think I’d PB by that much, not at all. An island record is the icing on the cake, so I’m over the moon.”
Mackay and Saunders complete Jersey sprint line-up
Jersey’s Steven Mackay, the previous 100m record holder, also competed in the heats and recorded a season’s best time of 10.68 seconds.
Mackay finished fifth in his heat, which was comfortably won by Jamaica’s Rohan Watson. His time placed him 46th overall in the rankings.
The third Jersey sprinter, Zachary Saunders, also returned to Commonwealth Games competition after representing the island four years ago.
Saunders recorded 10.72 seconds to finish fifth in his heat and ranked 49th overall. He was 0.56 seconds behind South Africa’s heat winner Bradley Nkoana.
Despite missing out on progression in the 100m event, all three Jersey athletes will have another opportunity to make an impact when they compete in the men’s 200m heats on Wednesday.
Oldham’s record-breaking display has already provided a historic moment for Jersey athletics, with the young sprinter establishing himself as one of the island’s leading talents on the international stage.