This was a joint publication by DC and Marvel Comics. DC Published #1 and #4 and Marvel published #2 and #3. Superheroes and super-villains from both companies came into contact with each other and interacted as the result of two cosmic figures known as the Brothers. This was the first in-continuity cross-over between the two companies as previous cross-overs were not subsequently referenced in regular continuity.
The main heroes from each universe were matched up against each other and the winner was determined by a fan vote. At the time Marvel’s X-Men was extremely popular and Wonder Woman was experiencing a lull in her popularity. As a result Diana was paired against Storm, who she clearly outmatched in fighting prowess and strength. Never-the-less, to the shock and incredulity of Wonder Woman fans worldwide, Diana lost the fight after being struck down by a humble lightning bolt.
The Editorial teams would later try to justify the defeat as being result of Wonder Woman being susceptible to electricity, which fans knew was utter rubbish and merely an excuse.
Wonder Woman would get redemption of sorts in the DC/Marvel All-Access mini-series published a year or so later, where she also makes it clear to Storm that she had only won their previous confrontation because she had taken Diana “by surprise”.