A goal of magisterial quality from James Milner gave Aston Villa the edge in their Carling Cup semi-final first leg, but there remains everything to play for when the tie is concluded next week.
As the best player on the pitch, it was fitting that Milner's goal should involve him going almost the whole length of it in a way that spoke volumes for his vision as well as his lung capacity.
"It was a great goal from a great player," said his manager, Martin O'Neill. "He's taken to playing in central midfield with such confidence, as though he has played there his whole career."
His team's failure to add a second when they were dominating left the door open for Blackburn, however, who hit the post twice through Nikola Kalinic in a much-improved second-half performance after Villa had threatened to overrun them in the first 45 minutes.
"I thought overall we deserved at least a 1-1," said Sam Allardyce, who has now seen his Blackburn side fail to win in nine games since knocking Chelsea out in the quarter-finals of this competition. "It's our Achilles' heel yet again, with millimetres of woodwork denying us a goal."
On yet another icy night and on an Ewood Park pitch that looked to be on the hard side of unyielding from the start, the first half-chance fell to Blackburn's David Dunn, whose low shot on the turn was deflected wide.
There was also an early warning of the expansive width with which Villa are capable of playing in the way that Stewart Downing picked out Ashley Young with a cross-field ball only for Young's shot to be blocked. There was quality too in the way Milner and Emile Heskey set up Stilian Petrov, but his shot carried no sting.
When the goal Villa were threatening did arrive, it was a tour de force from Milner. Collecting the ball in his own penalty area as Blackburn's threat from a corner fizzled out, he surged upfield to find Downing on his less accustomed right wing. Milner just kept running and was there to sweep the ball into Paul Robinson's net from close range when Downing slid in a low cross – a foray by the England player of a good 90 metres.
Blackburn could have been at least two down by half-time, the referee Mark Clattenburg booking Gabriel Agbonlahor for diving when he could equally well have given a penalty for Chris Samba's lunge – a decision O'Neill called "ridiculous" – and Robinson saving acrobatically from Petrov's shot and Carlos Cuellar's header.
"Big Sam, Big Sam, sort it out," chanted some Blackburn supporters. As is the nature of such advice, they did not say how, although it was reasonably obvious that some support for Kalinic, labouring on his own up front, would not come amiss.
The introduction of Martin Olsson at half-time and a reshuffled back four did not really seem to address that problem. Indeed, it could have seen matters worsen when Young skinned the newcomer with pure pace and then put his cross almost along the goal-line.
The sole Rovers front-runner could have had an equaliser after 54 minutes, however, when he met Morten Gamst Pedersen's cross, but Kalinic's header came back off a post. Dunn also put a shot wide as Blackburn stepped up their efforts appreciably.
Kalinic was desperately close again when he hit the upright with a measured shot from Pascal Chimbonda's centre. Villa still looked classy and dangerous on the break, but Blackburn had seized much of the initiative and brought on Benni McCarthy, considered fit enough for a place on the bench, to try to grab a leveller.
It was Brett Emerton who went closest to doing that, with a shot clawed away by Brad Guzan in the Villa goal. Steven Nzonzi also headed over as time ran out, but Rovers had shown the fight they will need at Villa Park next week.
"I can't stress any more that I think the tie is still in the balance," O'Neill said. Maybe, but thanks to Milner it is a balance which is tilting unmistakably Villa's way.
Blackburn Rovers (4-5-1): Robinson; Jacobsen (Olsson, h-t), Samba, Nelsen, Chimbonda; Salgado (Reid, 71), Emerton, Nzonzi, Pedersen (McCarthy, 75), Dunn; Kalinic. Substitutes not used: Brown (gk), Hoilett, Di Santo, Jones.
Aston Villa (4-4-2): Guzan; Cuellar, Collins, Dunne, Warnock; A Young, Milner, Petrov, Downing; Heskey (Sidwell, 71), Agbonlahor. Substitutes not used: Friedel (gk), L Young, Carew, Delph, Reo-Coker, Beye.
Referee: M Clattenburg (Tyne & Wear).