Before kick-off Derby County manager Jim Smith calculated his team needed two wins from their remaining games to preserve their Premiership status and, apart from a couple of second-half sorties from Leicester, there were rarely any doubts that this would be one of them.
The victory - courtesy of Paul Boertien's first Premiership goal and Stefano Eranio scoring what could be his last goal for the club before he returns to Italy - leaves Derby five points clear of the bottom three with four games left.
Their superior goal difference to Coventry City effectively extends the safety margin to six points, but Smith's chickens remain firmly uncounted. "Four or five weeks ago I said 38 points would be enough to see us safe but we're now looking at 41," Smith said.
With fixtures against Manchester United, Arsenal and Ipswich Town to come, Saturday's visit from bottom-of-the-table Bradford City is the most likely source of salvation.
County always looked the likeliest winners and Boertien's right-footed strike in the 24th minute confirmed their dominance. The defender's goal followed fine work by Eranio, who ended a mazy run by sliding the ball past Simon Royce.
The hosts were rarely troubled apart from two headers that followed corners shortly after half-time. Gary Rowett saw his cleared off the line by Chris Riggott and Royce tipped Arnar Gunnlaugsson's to safety via the crossbar.
But City's revival was as brief as it proved unproductive and added up to another dismal day for their manager Peter Taylor.
The defeat means his team have lost 10 on the bounce away from home and six in succession anywhere - a run that has probably wrecked their hopes of qualifying for Europe.
DERBY: Poom, Carbonari, West, Riggott, Delap, Eranio, Powell (Gudjonsson 30), Johnson, Boertien, Kinkladze (Christie 75), Burton, Gudjonsson (Mawene 90). Subs Not Used: Morris, Grant. Sent Off: Burton (90). Booked: Delap, Kinkladze, Carbonari, Boertien. Goals: Boertien 24, Eranio 90.
LEICESTER: Royce, Rowett, Elliott, Davidson (Oakes 72), Impey, Lewis, Savage, Eadie, Guppy (Gunnlaugsson 45), Akinbiyi, Benjamin (Marshall 45). Subs Not Used: Flowers, Delaney. Booked: Eadie, Elliott.
Referee: M Halsey (Welwyn Garden City).
