Steve Stone made his long-awaited Leeds debut as David Healy's 74th-minute winner handed Kevin Blackwell's men their first win in nine games.
Former England winger Stone entered the fray shortly after 61 minutes to end a nightmare spell on the sidelines.
He arrived at Elland Road on a free transfer from Portsmouth last summer but sustained an Achilles injury during his first training session.
Stone is now edging towards full fitness and his introduction had the desired effect as Leeds claimed the points 13 minutes later when Healy headed home Gary Kelly's cross. The return to fitness of Stone is a significant boost to Leeds ahead of their crucial play-off encounters, though they made heavy work of dispatching of relegated Crewe.
Stone began on the bench while Blackwell made two changes to the side which drew 1-1 at Sheffield United on Tuesday.
Former Crewe striker Rob Hulse was rested and Jonathan Douglas relegated to the bench with Eddie Lewis and Danny Graham restored to the starting XI.
And it was the recalled duo who combined to create the first goalscoring opportunity after three minutes.
USA winger Lewis broke into the box from the left flank and chipped in a dangerous cross but Graham headed over the bar from just six yards.
Leeds were beginning to dominate and came even closer to scoring after 10 minutes when left-back Stephen Crainey fired inches wide from 25 yards.
Crewe boss Dario Gradi, who made four changes to the side which drew 1-1 with Cardiff on Easter Monday, watched his side struggle to cope with Leeds' tenacious approach.
Healy warmed Crewe goalkeeper Ross Turnbull's hands from distance with a stinging effort as the hosts threatened a breakthrough.
And midway through the half Sean Derry charged past a clutch of players into the box and drove a fierce cross-shot across the face of goal - but none of his team-mates gambled and the opportunity was lost.
Crewe did not pose a serious threat to Leeds' goal until shortly before the half hour mark when Gareth Taylor shot over from the edge of the 18-yard box.
But Leeds continued to attack and Derry showed neat footwork to engineer a shooting chance 20 yards from goal before Liam Miller's effort was blocked by Crewe defender Majid Bougherra.
Leeds then suffered a blow three minutes before the break when on-loan Middlesbrough striker Graham was forced off injured and replaced by Ian Moore.
Crewe initially began brightly after the restart and Luke Varney drew a fine save from Neil Sullivan but Leeds slowly regained the ascendancy.
And when Stone replaced Miller after 61 minutes, Leeds were reinvigorated and struck the all-important opening blow after 75 minutes.
The impressive Gary Kelly swung in a dangerous cross from the right flank which Healy headed home in emphatic fashion for his 14th goal of the season.
Having stumbled into the play-offs, Leeds fans could at least celebrate a long-awaited victory in their final home match of the season to lift spirits ahead of the crucial play-off semi-final encounters.
Teams:
Leeds Sullivan, Kelly, Butler, Kilgallon, Crainey,Miller (Stone 61), Derry, Bakke, Lewis (Blake 66), Healy,Graham (Moore 41).
Subs Not Used: Gregan, Douglas.
Goals: Healy 74.
Crewe Turnbull, Moss, Bougherra (McCready 81), Foster,Otsemobor, Bell (Roberts 86), Lunt, Johnson, Vaughan,Taylor (Higdon 82), Varney.
Subs Not Used: Tomlinson, Rodgers.
Att: 21,046
Ref: N Miller (Co Durham).