See Gohan vs Future Trunks Part 1 for what happened last time....
Trunks recovered before he hit the ground and turned around and fired a Burning Attack at Gohan. Gohan did a two arm block and blocked it. Then Trunks was behind Gohan and Trunks delivered a powerful blow to Gohan. Gohan was sent flying, then turned around and fired a Kamehameha. Trunks saw this coming and fired a Finish Buster at the same time. The two beams clashed, but in the end Gohan's won. Gohan had won the fight!