Everything that could go wrong for Rovers did, but while Albion have no fears of relegation, their biggest worry remains the future of their manager Roy Hodgson. He made it clear yesterday that he could sign a new contract in the coming weeks but, with reference to the England vacancy, also spoke of necessary safeguards.
"What West Brom would do – and I'm jumping the gun, I guess – is have clauses and compensation agreed," he said. "I'm not giving any thought to it and the vacancy has nothing to do with me, other than I'm an Englishman and have to answer questions about it.
"I'm very comfortable about the situation," he added. "If it gets done at the end of the season, or gets done before, that's fine."
Hodgson managed a seventh-placed Premier League finish in his time as Blackburn manager. What they would give for such assurance now after this defeat brought back bad memories of the Steve Kean era. The deterioration in their goal difference and the stoppage-time sending-off of Anthony Modeste were additional hardships they could have done without.
Blackburn recently won at Wolverhampton Wanderers for the second time in 10 months and, at The Hawthorns 16 months ago, gave Kean his first victory as their manager.
The only similarity between that happy occasion and this sobering one was the fact they ended with 10 men, Modeste being red-carded for a kick at Billy Jones' heels 12 minutes after his introduction. The shove into Simon Cox's chest by way of a follow-up didn't help but Lee Probert's mind was probably made up already.
By then, Albion's job was done. They didn't need to play particularly well in completing a League double over opponents who are up against it in a six-game run-in with trips to Chelsea and Spurs as well as Tuesday's home game against Liverpool.
Kean has never lacked confidence in his abilities, even amid the mid-season mood of rebellion at Ewood Park, and said last night: "We had 17 attempts at goal, 11 on target. In the first half we never got any intensity or momentum and we ended the game poorly. In between, there was a good response and we felt aggrieved we hadn't scored when we had the possession and chances. If Manchester United beat QPR, though, there's not much ground lost. We've had a bad day but we might get away with it."
Blackburn could certainly have chosen a better time to register three successive defeats and the fact they recently appeared to be clawing their way out of trouble before slipping back in is hardly a blessing.
Here, both managers agreed that Ben Foster's outstanding 55th-minute double save was a game-changer. Not content with getting down quickly to his right to beat out Yakubu's shot with a strong left hand, the former England man was up in a flash to block the follow-up from Bradley Orr. One goal separated the teams at the time and Albion subsequently ran away with a game that they had seized hold of early on.
The breakthrough came in the sixth minute, from their fourth corner. Gareth McAuley climbed highest to meet Chris Brunt's delivery but his downward header was unlikely to have gone in had Martin Olsson not diverted it into his own net.
Blackburn's Achilles heel this season, as recently as last Monday, has been the concession of late goals rather than early ones but this was a slow start. Their hopes were lifted by Junior Hoilett. One fine run ended with a shot the Canadian curled a yard wide of the angle from near the edge of the area and a second set David Dunn up for a side-footed effort that brought a decent save.
Albion, having gone four Premier League matches without a victory for the first time in Hodgson's reign, were fitful rather than convincing.
Jones advanced beyond Marc-Antoine Fortune and Peter Odemwingie before Youssouf Mulumbu's effort was too close to Paul Robinson from 20 yards after Fortune's pass.
Blackburn dominated either side of half-time, only to fall further behind at the three-quarter stage when Jonas Olsson challenged for Brunt's right-wing cross and left Fortune unmarked to drive home at the far post.
A third goal that Hodgson admitted flattered Albion came six minutes from time when Liam Ridgewell glanced home a header from Graham Dorrans' free-kick. Modeste compounded Blackburn's misery by retaliating at Jones after the full-back kicked the ball away at a throw-in. "The ref says there was intent but Anthony went to kick him and changed his mind," Kean argued. "There's the possibility of an appeal."
West Bromwich (4-1-3-2): Foster; Jones, McAuley, Olsson, Ridgewell; Mulumbu; Brunt (Cox 82), Andrews, Dorrans (Scharner 88); Fortune (Long 90), Odemwingie.
Blackburn (4-2-3-1): Robinson; Orr, Dann, Hanley, Martin Olsson; Nzonzi, Lowe (Formica 78); Pedersen (Modeste 78), Dunn, Hoilett; Yakubu.
Referee Lee Probert.
Man of the match Dorrans (West Bromwich).
Match rating 6/10.