Russell sat just off a fair gallop set by Ruby Walsh on Celestial Halo but the distress signals were soon being sent out on last year's Champion Hurdle runner-up. Sublimity briefly looked a threat, but Solwhit powered away for a four-and-a-half-length win from Donnas Palm, who caught Sublimity on the line for second.
Totesport now make Solwhit their 7-2 favourite for the big one with Paddy Power even more impressed at 3s.
Byrnes said: "He's absolutely brilliant to jump – the fastest jumper I've ever had. Hopefully we'll get him in the same form for Cheltenham."