Nottingham Forest 3 Bristol City 2: City boss Gary Johnson insisted the sending-off of Jamie McAllister had cost his men this game.

The left-back saw red for a second bookable offence after a controversial series of events that sparked Forest's comeback from 2-1 down to a 3-2 victory.

Moments earlier, McAllister, who had been booked for a first-half foul and also been involved with some further pushing and shoving with his opponents, was looking like a City hero.

He had provided the long chip into the box for Dele Adebola's header that gave the Robins the lead for the second time.

But City's self-inflicted troubles began when goalkeeper Adriano Basso caught a cross and went down, apparently with cramp, and called for treatment.

The Robins decided to kick the ball out for a throw-in to allow the Brazilian to be seen to.

On the restart, which was on the opposite touchline to Johnson's dug-out, McAllister and his colleagues seemed to be surprised that Forest did not adhere to the accepted custom and throw the ball straight back to City's keeper or out for a goal-kick.

Instead Chris Gunter threw the ball in the direction of McAllister and then closed him down quickly. The Scotland international's clearance was blasted straight at Gunter and looped up to the winger after he had got past McAllister. The former Hearts man wrestled Gunter to the floor and a second yellow was inevitable.

From the free-kick, Lewis McGugan's cross was forced in at the near post by the head of substitute Joe Garner.

Forest's actions were clearly unsporting – when Arsenal scored an FA Cup winner against Sheffield United in similar circumstances Arsene Wenger immediately offered the Blades the chance to replay the game.

But a pragmatist could hardly blame the relegation-threatened side for stooping a little low and, to his credit, neither did Johnson.

"It was a very strange end," he admitted. "It is football at this level and it certainly typified our season.

"We have gone from a winning position to a losing position and mistakes at this level – especially two or three on the trot – cost you.

"I felt we didn't need to be going down to get treatment, we didn't need to be kicking it out of play and we didn't need to be taking two touches (before clearing) when there is five minutes to go.

"Someone is bound to throw it to you and shut you down. Credit to them because they took advantage of the mistakes.

"You mustn't cry over it – you have to defend it. Once again we have lost somebody in the area and they have scored their goal."

Johnson admitted he had told McAllister he had cost City the points and he confirmed that the player did not agree.

He added: "Jamie is a whole-hearted player who has had a great season for us and he is obviously upset himself, but of course when someone gets sent off it costs you the game.

"The turning point was the sending-off. I said to Jamie, I think the sending-off has cost us the game. He has been a great player for us and very consistent and he doesn't feel it cost us the game. But we were 2-1 up at the time.

"On other days it has been another of our players who made a mistake that led to an opportunity. At this level you have to cut out the mistakes."

With a draw no good to either side, both teams went hell for leather for a winner in a breathless finale.

But the momentum was with Forest against 10 men and it was no major surprprise when a bout of head tennis in the City box ended with Dexter Blackstock's stunning last-minute volley searing past Basso.

Blackstock hurled his shirt into the crowd before jumping into the Trent End while City's players sank to their knees.

Johnson's men had been celebrating their good fortune earlier when they were gifted the lead on 13 minutes by Forest's on-loan Everton keeper Iain Turner.

Lee Johnson's cross from the left dropped low at the feet of Turner, who fumbled the ball under pressure from Adebola and a defender, allowing it to roll into the path of Ivan Sproule, who had the easy task of walking it into an empty net.

Jamie McCombe almost doubled the visitors' advantage soon after but Turner half-redeemed himself by plunging to his left to tip the centre-half's header away from goal.

But another howler gave Forest their leveller when McCombe failed to deal with a ball over the top that he should have easily cleared.

The bounce seemed to decieve the big man and Rob Earnshaw was able to nip in and fire past Basso.

Forest had much the better of the early part of the second half but City asserted themselves and Sproule should have given them the lead when he surged past Turner, who for some reason chose to come for a ball he had no chance of winning.

But Sproule rushed his shot from the right side of the box and Kelvin Wilson easily got back to clear off the line.

Then substitute Gavin Williams was played in by Michael McIndoe but his shot from the other side of the area bounced back off Turner's legs.

City's pressure told when Turner again went AWOL as he tried to punch McAllister's lob into the box but was beaten by the head of Adebola, who glanced it over him and into another unguarded net.

With Preston having lost earlier in the day, the Robins were feeling the play-off dream may become reality. But a lack of concentration not untypical of this side cost them when it really mattered.

Johnson said: "If there was a neutral in the crowd it would have been a good game because there were loads of chances both ends. One minute you are up and the next minute you are down. If it had been the start of the season we would all have been saying what a great game that was.

"But it is not and it has cost us. It is a shame. We will have to see where Forest end up after 46 games."

Nottingham Forest (4-4-2): Turner; Gunter, Wilson, Morgan, Lynch; Anderson, Perch (McGugan 80), Moussi (McCleary 61), Cohen; Earnshaw (Garner 71), Blackstock. Subs not used: Smith, Chambers.

Bristol City (4-4-2): Basso; Orr, McCombe, Fontaine (Iriekpen 46), McAllister; Sproule, Skuse (Elliott 66), Johnson (Williams 66), McIndoe; Maynard, Adebola. Subs not used: Henderson, John.