Greenman vs. Seguro No. 1 (グリーンマン対セグロ1号, Gurīnman tai Seguro 1-gō?) is the twenty-sixth episode of Go! Greenman.
After a short discussion between Maoh and Tonchiki, a robotic kaiju called Seguro No. 1 appears directly behind a young girl and grabs her, sending the remaining children running. However, they run in Tonchiki who is also there. A boy does manage to escape though, and activates a Green Call. Greenman appears in a flash and begins beating on Tonchiki before pursuing Seguro No. 1. He manages to free the girl from Seguro's grasp and begins to fight. They gradually make their way down a hill whilst fighting and continue exchanging hits at the bottom. Eventually, Tonchiki realizes that Greenman is somewhat winning and orders Seguro to grow. Greenman uses his electronics to grow as well and they re-engage combat in a flat, sandy area. Greenman quickly knocks Seguro down, but he doesn't get up no matter how much Greenman kicks at him. Convinced his work was done, Greenman continues walking away but is struck in the back by Seguro's metal claw. Knocked to the ground and kicked down a steep slope, Greenman lies on his back taking multiple hits until he is flung to his feet by the arm and thrown down once more. Greenman returns to his feet again only to be beat on and thrown down for the third time! Greenman is also further rolled down the slope and repeatedly punched in the face. Plus, to make matters worse, Seguro emits a powerful red light which damaged Greenman even more. Much to Tonchiki and Maoh's amusement, Seguro continues pummeling Greenman. But, the monster gets too cocky and Greenman manages to seize Seguro whilst he is distracted. With only a few strong blows and an Ear Boomerang, Seguro No. 1 is down for the count.