"In this same year, when two galleys belonging to the Pisans had gone armed to Constantinople, and prolonged their stay there, some men from these galleys made an attack on two Genoese who were at Constantinople." Genoese compatriots heard of the assault, ran to the scene, "and thrashed some of the attacking Pisans." The Pisans manned one of their galleys and sailed into the Black Sea, initially to the coast off Sinop, where they awaited an opportunity to exact revenge. Meanwhile, a Genoese galley that just docked at Pera (the Genoese enclave at Constantinople) heard of the events and "immediately began to pursue the aforesaid Pisans' galley, and, with favorable winds, they arrived at Sudak. And while they tarried there, the aforesaid Pisan galley unexpectedly caught up with them on the Eve of Blessed Mary in the month of August." The Genoese sailed out to attack, and "a very harsh battle was engaged between them in sight of the people of Sudak. For when the battle had been started, one mile off shore, they all went out to see; and thus God willing, our galley thence brought back victory; and having received the Pisan merchants who had survived the battle, and placed them on land with their goods, they burnt the galley of the Pisans in view of all."
Read the latin version on the project's website.