The game ended 9-9, a point apiece ensuring Croydon's progress to Championship 1 but keeping alive Sutton's hopes of avoiding the drop into a bottom three placing and relegation to Championship 2.
With less than four minutes remaining, Sutton edged into a 9-8 lead with Dicken McLean's fourth goal. Alfonso Tucay equalised immediately afterwards - his sixth - and, although both sides took a late time-out, there was no further scoring.
In Division 4, seven-goal Declan Thompson was again the key player for Castleford in their 16-14 defeat of South Derbyshire. Castleford led 9-5 and 15-11 but were sweating near the end as South Derby caught up to 15-14 with goals by Paul Gregory (2) and Neil Swainson. Luke Franks' strike with 22 seconds remaining settled the Castleford nerves.