Hull twice fought back from two goals down to inflict a potentially fatal blow on Bristol City's Championship play-off hopes in an amazing 5-5 draw at Ashton Gate.Fraizer Campbell slid home an 87th-minute goal from a cross by substitute Kamil Grosicki to put the visitors ahead 5-4 after they had trailed 3-1 and 4-2.But during six minutes of stoppage time, Joe Bryan cut in from the left to equalise with a low drive from just outside the box. There was still time for Robins goalkeeper Frank Fielding to save from Abel Hernandez as a crazy game reached a costly conclusion for the hosts.Harry Wilson fired Hull into a 16th-minute lead, accepting a return pass from Jackson Irvine and hammering a left-footed shot past Fielding into the top corner.But the hosts were level on 37 minutes when, after a period of pressure, the ball broke to Marlon Pack in a central area 30 yards out and he moved forward to strike a low right-footed drive past Allan McGregor.Three minutes later the home side went ahead through club record-signing Famara Diedhiou, who held off a challenge from Michael Dawson when the ball dropped to him in the box and took his time before hammering home a left-footed shot.Diedhiou notched his second eight minutes after the break, producing a perfectly placed header from Bobby Reid's left-wing chip and directing the ball inside the far post from 10 yards to make it 3-1.But Hull were back in it almost immediately as substitute Fikayo Tomori headed a diagonal ball from Angus McDonald against a post and the ball went in off Fielding for an own goal.On 64 minutes, Reid ran onto a through ball and got between Angus McDonald and the advancing McGregor to slot his 21st goal of the season.Still Hull refused to buckle and the impressive Wilson made it 4-3 with a 30-yard free-kick from the right that beat Fielding at his near post.Ten minutes from time it was 4-4 as Hernandez fired home a low cross from fellow substitute Grosicki. The game finished like a basketball match with both sides looking set to score from every attack.The first half saw the Robins create the better chances. Callum O'Dowda had a close-range volley saved by McGregor in the opening minutes after Jamie Paterson's chip had created the opening.McGregor made a brilliant save from his own defender Stephen Kingsley, who inadvertently nodded on a Reid header.The Robins were unlucky on 33 minutes when Paterson turned neatly just outside the box and saw his deflected shot come back off a post.But on a day they needed a win to keep play-off hopes flickering, Lee Johnson's men were found badly wanting defensively.