(FORTUNE Magazine) – Holy athletic footwear! In this summer's runaway hit movie, Batman wears boots designed by Nike. The hero here is mild-mannered Tinker Hatfield, 37, creative director for product design at the $1.7-billion-a-year sneaker seller. The movie's costume designer called in Hatfield to create a menacing but functional Bat-boot for actor Michael Keaton and several stuntmen. Working from a plaster cast of Keaton's calves, Hatfield made 18 pairs of knee-high leather-and-polyurethane boots, which look a bit like the footwear that Nike sells to ordinary mortals. Says Hatfield: ''They are basically athletic shoes with a boot on top.'' A nationally ranked pole-vaulter while at the University of Oregon, Hatfield joined Nike as its corporate architect in 1981. He switched from drawing buildings to fashioning shoes three years later. His work is helping Nike close in on Reebok (1988 sales: $1.8 billion) for the lead in the footwear race. Under Hatfield's direction, Nike's 50 designers constantly tinker with the looks and performance of the popular Air Jordan and Cross Trainer shoes. Next year's version of the Air Jordan, for example, will have the same form- fitting ankle cushion as the Bat-boot. Its price: a wicked $125 a pair.