Only Andreas Almgren has run the distance faster, at 7:34.31 minutes.
Sundström squeezed in as the new second on the Swedish best list and pushed Emil Danielsson down to third place by four hundredths.
"It was fun to feel strong and the feeling is that I've taken a step forward after good training during the autumn and winter," says Sundström to friidrott.se.
A start like this to the year means a lot, to feel that I'm getting good responses to my training and am on the right track towards the summer.
Simon Sundström finished second in the competition and Leo Magnusson became fifth at 7:55.21. German Frederik Ruppert won with a new personal best, 7:46.69.
Sundström's previous personal best on 3,000 meters indoors was 7:51.30 and was recorded at the European Championship in Istanbul 2023.