North Down's Reynolds clocked 7.77 in the 60m hurdles to edge under the required 7.80 for the European Indoor Championships in Belgrade next month.
Portaferry athlete Mageean won the 800m in 2:06.02 but it was well short of the Belgrade qualifying mark of 2:03.75.
Kerry O'Flaherty clinched 1,500m victory in 4:16.04 and Adam McMullen won the long jump with 7.48m.
Rio Olympian O'Flaherty overhauled in-form Queen's athlete Emma Mitchell over the closing laps in the race of the day with the runner-up finishing in 4:17.42.
Both runners were chasing the European Indoor 1500m standard of 4:15.00 with Mitchell having set her personal best of 4:16.20 when winning the Scottish Indoor title last week.
Derry man McMullen needed a jump of 7.90 to qualify for the European Indoor Championships.
Meanwhile, Holywood's Paul Pollock was in good form in Japan with a marathon personal best of 2:15:30 and a qualifying time for the World Championships in London in August.
Ben Reynolds and Ciara Mageean secured victories in the AAI Games at the new National Indoor Arena on Sunday.