A European indoor silver medallist a year ago, Petersson came into these championships as one of Sweden's main hopes, and he looked capable of delivering during the morning's qualification, finishing fourth with a best throw of 20.47m, though sadly his fellow Swede, Leo Zikovic, was unable to crack the top 12 and join him in the final.
At the business end of the competition, Petersson was sitting outside the medal places at the halfway mark with a best of 20.44m from his first attempt, before improving significantly with his fourth throw of 20.86m to go into third place.
A bronze medal was secured when Great Britain's Scott Lincoln failed to improve on 20.81m with his last attempt, and with the pressure off, Petersson produced a 20.97m throw to finish his competition, though that still wasn't enough to surpass the gold and silver medallists from Italy - Leonardo Fabbri and Zane Weir.
There were no issues for Sweden's medal hopefuls in qualification for the women's shot put, either. This year's world indoor bronze medallist Axelina Johansson cleared the automatic qualifying distance of 18m with her first throw, registering 18.12m. Fifth at last year's world championships, Fanny Roos went even better with her first attempt, throwing 18.72m.
The duo finished qualification in fourth and seventh, respectively, but a best throw of 15.84m from Victoria Wickman wasn't enough for her to be among the 12 finalists.
Johansson was only able to add a few centrimetres in the final - producing a best of 18.18m with her second attempt to finish 10th. However, Roos went much better again in the final, sitting fourth after two throws with a best of 19.05m.
Yet she was unable to improve with her next four attempts, and had to settle for fourth place. In the end was still a fair way down on Germany's Yemisi Mabry, who took bronze with 19.50m. Atop the podium was a Dutch one-two, as Jessica Schilder's 20.73m was well clear of the personal best of 19.64m from compatriot 19.64m
Swedes progress on the track and field
Moa Granat could only finish fourth in her 400m hurdles heat, but her season's best of 56.11 was actually the ninth-best time overall, booking her a place in 11th August's semi-finals. Meanwhile, a time of 57.03 wasn't enough for Tilde Bjerager to make it through.
Despite spending plenty of time on the sidelines recently, Andreas Kramer put in a season's best performance of 1:46.05 to finish second in this 800m heat and progress to the semi-finals.
Also progressing was Maja Askag, who is through to the final of the women's long jump on 13th August after saving her best jump - 14.21m - to last and place sixth in qualification. 13.46m was not enough for Emilia Sjostrand to finish amongst the top 12.
Montler misses out by a centimetre
There was disappointment for former world indoor silver medallist Thobias Montler, who missed out on qualifying for the men's long jump final by 1cm, as his final jump of 7.90m was only enough for a 13th-placed finish after Czech Republic's Petr Meindlschmid jumped 7.91m having fouled his first two attempts. With a best of 7.93m, Niklas Wall finished 23rd in the 30-strong field.
In the men's hammer, Ragnar Carlsson produced two fouls with his first two attempts, and though he did register 68.54m with his final attempt, he was still well off the distance needed to reach the final.
Away from the stadium in Birmingham, there was bad news for pole vaulter Oliver Sandberg, who will miss the championships. His pole broke during training, causing injuries to his wrist, back and neck when landing awkwardly.