Riccardo Saponara and Empoli were frustrated by Bologna in a mid-table goalless draw at the Stadio Carlo Castellani.The Tuscan side were dominant and might have scored through Piotr Zielinski, the Polish playmaker fluffing a one-on-one with Antonio Mirante.Saponara missed two gilt-edged chances after the break and, in the 64th minute, demanded a penalty when he was fouled in the Bologna box as he played the ball forward for Daniele Croce to convert from an offside position.The former AC Milan player could even have grabbed a late winner when seizing upon Zielinski's through ball, but he shot wide.