A woman who saw the fatal attack on Bristol teenager Joe Dymond-Williams was herself knocked out as she tended to his unconscious body, a jury has heard.

Nicola Grant told Bristol Crown Court she was sickened as Joe's head hit the floor with "an almighty crack".

Joe, a 17-year-old St Brendan's Sixth Form College student, got involved in an argument between former couple Jack Pullin and Sophie White, when Jack Sanderson-Hunt and Thomas Swift waded in, the court has heard.

Sanderson-Hunt punched Joe to the ground on Queen Charlotte Street before Swift kicked him in the head, the court has heard.

The two defendants, both now aged 18, each admit the manslaughter of Joe, from Whitchurch.

Sanderson-Hunt, of Dundry View, Knowle Park, is waiting to be sentenced.

Swift, of Ellfield Close, Bishopsworth, is standing trial for murder, which he denies.

Miss Grant said she had been out drinking with her boyfriend Gareth Bevan at the Llandoger Trow on King Street, leaving in the early hours of June 22.

She told the jury: "As we left we heard some shouting and as we walked a bit further down we could see three boys, at which point we saw one boy punch another. The boy fell to the ground, like a dead weight – he just fell backwards."

As she tended to the unconscious Joe, Miss Grant said someone kicked him in the stomach and, "seconds later", the temple, but she couldn't see who was responsible.

She said: "I was mortified as I could see he was unconscious. How anyone could do that, I don't know."

Having stood up, the court heard Miss Grant was also attacked.

Mr Bevan said: "One of the girls on the scene stood up, ran towards Nicola and pushed her on the ground. Nicola fell back, hit her head and was motionless on the floor."

At least five witnesses told the jury they saw a boy in a green top, accepted to be Swift, kick Joe in the right side of his head "like a football" while he lay motionless.

One of the witnesses, Samuel Ross, said Swift held his head in his hands soon afterwards.

He told the jury: "He seemed quite fired up at the time but once he had done it he realised what he had done, basically, and seemed in shock."

After the attacks on Joe, the court heard Swift moved away, along King Street towards the city centre.

But another witness, David Ross, who had been celebrating a friend's birthday, pursued him.

Giving evidence, he said: "I've seen fights – you see them every Friday night – you don't get involved. But when I saw this lad out cold and he gets kicked in the back of the head, something just clicked and I went for the lad that kicked."

With the help of another man in a black hooded top, David Ross said he confronted Swift as Sanderson-Hunt, his knuckles covered in blood, told his friend to run away.

David Ross said he told Swift he was "going nowhere", at which point he said the defendant looked like a "deer caught in headlights."

At one point Sanderson-Hunt got into a fight with the hooded man, who was trying to restrain him until police arrived.

But he eventually got away when he met a group of friends by the Waterfront.

Joe suffered a 10cm fracture to the back of his skull and a 3.5cm fracture to the right side of his skull.

He remained in a coma until July 8, when he passed away.

The trial continues at Bristol Crown Court.