Darrius Heyward-Bey -- Oakland Raiders Wide Receiver Pleads Not Guilty to DUI

Oakland Raiders wide receiver Darrius Heyward-Bey insists ... he didn't drive drunk on a San Francisco bridge last month -- pleading "not guilty" to DUI today in a California court.

As we previously reported, Darrius was charged with DUI a couple weeks ago -- after allegedly driving while intoxicated on the Bay Bridge early in the morning on April 7th.

According to police, Darrius was pulled over for speeding and weaving in his lane. Officers administered a field sobriety test ... and Darrius didn't do so well. He was cited for DUI and later released.