This is a strangely worded question but the answer is yes, instilling panic/fear in the enemy was the key to victory in many ancient battles.

One of the best examples is Gaugamela, Alexander the Great's army fought the army of Darius which was much, much larger. As the story goes, Alexander's whole left line was being overwhelmed when Alexander opened a gap on the Persian's own left side, charging his cavalry through the Persian infantry and running straight at Darius. King Darius fled the battlefield as Alexander turned back to relieve his own left. Seeing their own king flee Alexander surely caused a major drop in the morale in the Persian army, causing the rout of the much, much larger Persian force.

In most ancient warfare (such as Greek hoplite warfare), the very concept of a rout typically implies fear/panic. Ancient infantry was heavily dependent on maintaining the integrity of their formation. As soon as that formation was broken or became disorganized, the entire unit would flee the battlefield because it was doubtless they would be cut down by their still-composed enemy. So, armies could rely heavily on breaking the enemie's formation and causing a collapse of morale regardless of higher or lower numbers on the battlefield, but of course being outnumbered instills fear in itself. Some armies were an exception to this rule, such as the hit-and-run horsemen of the Asian steppes.

There are references of Greek soldiers being terrified the first time they encountered war elephants. To fight a war elephant they could not remain in a tight-packed formation, they had to surround the elephant and shoot it with arrows causing the elephant itself to panic. This breaking of formation must have been very against instinct and reportedly resulted in heavy losses.

Source: Alexander the Great by Philip Freeman.