Warren Sapp's Alleged Hooker -- Pleads Not Guilty to Hookery

One of the women Warren Sapp allegedly paid for "sex acts" on the night after the Super Bowl has pled NOT GUILTY to misdemeanor prostitution ... TMZ Sports has learned.

As we previously reported ... Sapp told the Phoenix PD he paid Britney Osbourne and Quying Boyd each $300 to come to his hotel room and perform "sex acts" on him on February 2nd.

Sapp said Osbourne performed oral sex on him (and he recorded it on his cell phone) ... but things went south when he asked for vaginal sex and she demanded more money.

Osbourne was later charged with prostitution. If convicted she could do time behind bars.

As for Boyd, she was charged with not having proper escort identification ... and she has also pled not guilty. She faces a fine if convicted.

Warren was charged with two counts of assault (for allegedly attacking Osbourne during the vaginal sex dispute) and one count of soliciting prostitution. If convicted, he faces up to six months in jail.

Sapp is due back in court later this month.