Everton's David Weir was taken to hospital after a sickning clash of heads which left the veteran defender unconscious on the pitch during his side's 4-0 win over Luton Town.
The injury - sustained in a collision with Leon Barnett - took the gloss off Everton's comfortable victory which sent them into the Carling Cup fourth round at the expense of a spirited Luton outfit who were given a lesson in finishing.
Luton boss Mike Newell cannot have enjoyed his return to his former club, witnessing his Championship outfit being well beaten in terms of the scoreline.
But all thoughts will be with Weir, who was carried off and taken to nearly Fazackerley hospital for an exploratory head scan, having regained consciousness in the dressing room.
Everton won thanks to first-half goals from Tim Cahill, a Keith Keane own goal and second-half strikes from James McFadden and teenager Victor Anichebe. They even missed a penalty.
Everton gave Scottish Under-21 goalkeeper Iain Turner a run-out, while also bringing in McFadden, Alan Stubbs and Leon Osman in changes to the side that beat Sheffield United at the weekend.
Luton, six games unbeaten, made one change from the side that thrashed Leeds 5-1 on Saturday, Keane replacing flu victim Markus Heikkinen.
Everton's lack of fit full-backs meant midfielder Davies was asked to fill in at right-back, and the midfielder did well in a position he has only really played before in a Wales shirt, and then only in a dire emergency.
Luton, who gave Liverpool a scare in the FA Cup last term, looked sharp and mobile and were certainly up for another crack at a Premiership side.
But Everton looked the more dangerous, and Davies produced a succession of dangerous crosses.
One was met by Cahill six yards out, and it looked a certain goal, but his header was deflected inches wide by the diving Leon Barnett.
Davies again set up Osman, but his fierce header was turned away by Marlon Beresford.
However, Everton went ahead two minutes later when Mikel Arteta's free-kick was headed back on at the far post by Joleon Lescott for Cahill to dive forward and nod home from a couple of yards.
Luton had their chances. Warren Feeney hooked just over from six yards and then the Northern Ireland striker forced Turner into an instinctive save.
But Everton were two ahead after 34 minutes. Johnson got past Keane on the left with a strong run to the byline before pulling back a low cross which was nudged first by Sol Davis, and then Keane before it deflected past Beresford.
Everton wasted the chance of a third goal when Johnson was pulled down by Keane, who was booked, and Beresford made a good stop from Arteta's penalty.
But Luton then saw a 20-yard Dean Morgan strike hit the post, before Weir and Barnett went up for a high ball and clashed heads.
It took five minutes of treatment before Weir was carried off with his head in a brace.
Youngster Mark Hughes came on to replace Weir in the second half, and Everton had two good chances within minutes to go further ahead.
First Beresford saved well when McFadden was clear, and then Morgan cleared a Stubbs header off the line.
But it was 3-0 after 53 minutes when Arteta and Cahill worked well on the left of the box, finding space far too easily, and the ball eventual fell to McFadden to stab home.
It could have been 4-0 soon afterwards when Johnson got clear on the edge of the box, but Beresford scooped the ball off his toes as the striker tried to take the ball past the goalkeeper.
Beresford saved superbly from a McFadden header, and then Arteta hit the post from 25 yards as Everton threatened to run riot.
Davies got in on the act and saw Morgan and Beresford scramble his 18-yard effort off the line.
Davies limped off after a challenge from Feeney, and was replaced by Anichebe. James Beattie replaced Johnson at the same time.
Anichebe's arrival had been keenly anticipated, and he immediately lashed in a fierce 15-yard shot which almost surprised Beresford.
Luton made a triple substitution with 10 minutes left, Adam Boyd, Ahmet Brkovic and Stephen O'Leary replacing Vine, Morgan and Robinson.
But with eight minutes left, and after Luton had wasted a good chance at the other end, Anichebe surged from halfway, twisting away from two defenders before drilling the ball past Beresford for the fourth goal.
