Snyders went faster than his time in Barcelona earlier in the week and only 0.2s off his season-best set at the trials in March, beating London Olympic 100m gold medallist Cameron van der Burgh (RSA) into third. The Kiwi was fourth in the 200m breaststroke in 2:14.44.
Kean clocked 54.95 to be second in the 100m backstroke to Frenchman Jeremy Stravius, the fastest man in the world this year, who won in a slick 53.19.
Fellow Capital club swimmer Samantha Lucie-Smith grabbed her first podium of the series with third in the women's 200m freestyle in a personal best 1:58.62 behind world championship short course gold medallists Katinka Hosszu (HUN) and Melanie Costa (ESP).
Another Wellington swimmer Samantha Lee won the B Final of the 100m butterfly in 1:00.35, a time that would have placed her seventh in the A final.
The meet concludes tomorrow.
Day 1 results:
50m breaststroke: Damir Dugonjig (SLO) 27.50, 1; Glenn Snyders (NZL) 27.61, 2; Cameron van der Burgh (RSA) 27.66, 3.
100m backstroke:
Jeremy Stravius (FRA) 53.19, 1; Gareth Kean (NZL) 54.95, 2; Juan Miguel Rando (ESP) 55.36, 3.
200m breaststroke:
Marco Koch (GER) 2:10.34, 1; Daiya Seto (JPN) 2:11.57, 2; Christian vom Lehn (GER) 2:13.15, 3. Also: Glenn Snyders (NZL) 2:14.44, 4.
(Sam Lee 1st B Final 100 fly, 1:00.35 (7th in final)
Women 200m freestyle:
Katinka Hosszu (HUN) 1:57.89, 1; Melanie Costa (ESP) 1:57.99, 2; Samantha Lucie-Smith (NZL) 1:58.62, 3.