How was Imperial Japan able to beat so many world powers starting from Tojo's victory over the Russian fleet?

First of all, Togo (Heihachiro) not Tojo (Hideki).

I'm not sure what you mean by "so many." They beat the Russians, yes, but the Russian navy was in pretty bad shape already -- it was falling behind technologically, and had some serious issues with command incompitance. Famously, one of the reasons Togo won at Tsushima was that a Russian hospital ship misidentified a Japanese scout ship as a friendly and began signaling the location of the rest of the fleet to it. The ground war against Russia was a disaster that was spun well in propaganda. The Japanese gained ground but were utterly unable to land a decisive victory against the Russians, and took terrible casualties doing it. The Diet actually threatened to shut off funding for the war to force a peace treaty, which was what convinced the leadership to take Teddy Roosevelt's offer to negotiate a peace.

The only other times the Japanese defeated Western powers was during the Second World War -- the French were under orders not to engage the Japanese during the occupation of Indochina, the British had the majority of their forces in Europe (though the fall of Singapore can be chalked up to some clever tactical maneuvering on the Japanese side), and the Dutch East Indies were only lightly defended. The Philippines fell because the Japanese had the element of surprise and an overwhelming numerical advantage -- to my understanding the Americans simply didn't expect the Japanese to be able to hit them so hard so fast. They (and many of these other powers) had a lot of racist assumptions about the strength of Japan's forces and what they would need to counter them. And that's pretty much the end of the "success" tally for Japan.

So I guess the tl;dr version is that the Japanese won their early victories out of a combination of dumb luck, exploitation of the geopolitical situation, and racist assumptions about what they were capable of.