New world indoor 60m hurdles champion Pozzi came sixth in the men's 110m final at the Gold Coast’s Carrara Stadium on Tuesday after an error-strewn run.
Hitchon, who won Olympic bronze in 2016, then failed to register a throw to finish last in the hammer.
Pozzi clattered the first two hurdles and never recovered as Ronald Levy took gold ahead of Jamaican team-mate Hansle Parchment and Australia’s Nick Hough.
The 25-year-old was left annoyed with himself for his mistakes.
“It doesn’t take a brain surgeon to see I should have been fighting for the medals,” said Pozzi, who qualified fastest but could only clock 13.53 seconds in the final.
“The standard is very good but that being said I was in good enough shape to win a medal.
“These opportunities don’t come up often so I have to wait another four years. I just wasn’t good enough.
“You look at it at face value. I hit too many hurdles. Right from the start I hit hurdle one, which is a stupid thing to do.”
England’s Hitchon then hit the net with her three attempts in the hammer to fail to record a score, the latest big name for England to struggle.
She said: “It’s part of the sport. I was utterly devastated after the world final last year but I told myself after London that I wasn’t going to cry.
“No one in 2014 thought I was going to win a medal in Rio, so two years out from Tokyo, I’ll be ready for it.”
Later, Caster Semenya destroyed the field to take the women’s 1500m title. The South African made her move with 300m to go and won in a Games record of four minutes 0.71 seconds.
She beat Kenyan Beatrice Chepkoech by almost three seconds while Wales’ Melissa Courtney came third and Semenya will now eye the 800m.
She said: “At the moment I can’t speak about the (800m world) record, I want to enjoy the championships – I don’t want to mess up anything. It’ll be a good race, the weather is great and after this 1500m I’ll say I’m ready.”
Meanwhile, Botswana’s Isaac Makwala took the 400m crown in 44.35s ahead of team-mate Baboloki Thebe and Jamaica’s Javon Francis.
In the pool, Ben Proud was left to rue the final three metres of his Commonwealth Games as England were beaten by Australia in the men’s 4 x 100m medley relay final.
Despite winning gold in the 50m freestyle earlier in the day, the 23-year-old was left with mixed emotions after being overhauled by Australia’s Kyle Chalmers in the relay
“I can’t help but feel disappointed looking at that last five metres,” Proud said.
“It was that little bit more that could’ve won the gold medal. The team did an amazing job and put me in a good position. I’m just sorry I couldn’t hold on for a little bit longer.”
Luke Greenbank kept England in contention on the backstroke and a blistering breaststroke leg from Adam Peaty saw James Guy take over on butterfly in the lead. Guy touched in 50.95, but Proud was hunted down by Chalmers, the Olympic champion at 100m freestyle.
In the women’s 400m freestyle final, England’s Holly Hibbott Ellie Faulkner took silver and bronze respectively having been pipped to gold by Australia’s Ariarne Titmus.
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