Sean Scannell was the toast of Selhurst Park as his last-minute chip gave Palace all three points.

The Eagles are now nine games unbeaten, but the 17-year-old substitute's late goal - his first for the first team - helped turn a point into three for Neil Warnock's men. 

For the first time since taking charge at Selhurst Park, Warnock kept faith with the same eleven from the previous outing.

That meant Danny Butterfield held his place at right back and Matt Lawrence was retained in a central defensive role.

Warnock even kept the same five substitutes that were in the dug-out at Barnley for last Saturday's sodden goalless draw, meaning youngsters Lee Hills and Scannell were again on the bench.

The weather at Selhurst Park was cold and bright and Palace came out of the blocks suitably fresh, with James Scowcroft coming close early on.

A feature of the early exchanges was the cut and thrust of Butterfield down the right. On six minutes he made a break and crossed for Morrison, who set up Watson for a close-range effort that was saved by Wednesday goalkeeper Lee Grant.

Wednesday took the lead with their first attack on 10 minutes. Glenn Whelan's long ranger was parried by Julian Speroni into the path of Richard Hinds. The Palace stopper did excellently to stop Hinds' first shot, but the rebound again fell to the same player to net from close range.

Palace countered and, on 18 minutes, Morrison squarded for Tom Soares to shoot low, but the outstretched left arm of Grant helped keep the ball out.

Play came to a drastic stop on 25 minutes when Frank Simek lunged for a ball down the Palace left. The Wednesday player was unchallenged but fell to the ground immediately with what looked like a serious knee injury.

The two-minute stoppage allowed Warnock and his opposite number Brian Laws to give their players detailed instructions.

But the home side struggled to create openings and it needed a crucial intervention by Clint Hill to prevent Marcus Tuday's cross from finding his intended target in the middle.

But on 37 minutes Palace grabbed an equaliser. Butterfield's right-wing cross was headed across by skipper Mark Hudson and Morrison stormed in to nod the ball into the net. Despite three minutes of stoppage time, there was little action of any note before Grant Hegley blew his half time whistle.

A good run and cross by Franck Songo'o on 49 minutes created a minor tremor in the Wednesday defence, but the ball was cleared, much to the dismay of the incumbents of the Holmesdale End that Palace were now attacking.

Although Songo'o was beginning to get more involved, it was he who was replaced by Scannell on 57 minutes, with the youngster taking up position in attack as part of a three-man strike force. 

A minute later, Tudgay had a rising long range shot tipped over well by Speroni. They came even closer after 61 minutes when Jermaine Johnson's 25-yarder clipped the top of the bar and went over.

Warnock then made another change, swapping Ben Watson for David Martin who, within two minutes, had forced a corner with a shot from distance.

The resulting set piece saw Hudson heading at the goalkeeper from Butterfield's cross. Either side of Grant and the close-range effort was surely bound for goal. 

Wednesday remained  a lingering threat though, and Lawrence managed to dispose of the ball at the second attempt after his clearance from a right wing cross fell invitingly to Steve Watson. 

An inspirational tackle and effort by Clint Hill on 78 minutes almost put Palace in front, but his rocket flew just over.

But the game could have swung either way, and Jermaine Johnson looked odds on to score when he streaked clear on 87 minutes. Fortunately for Palace, he dragged his right foot shot wide.

Wednesday were made to pay when, with 45 seconds of normal time remaining, Palace grabbed a dramatic winner courtesy of Scannell.

From Speroni's long kick, James Scowcroft flicked on to Morrison, who was blocked out by Grant. The ball fell to Scannell, who showed wonderful composure to dink the rebound into the net.

The Palace fans erupted into celebration as the players, led by Morrison, congratulated the 17-year-old's first goal in the professional game. 

Butterfield almost put the icing on the cake with a last-gasp free kick that flew inches wide.

But the Palace fans still went home happy after seeing a satisfactory conclusion to a rugged game.

Attendance: 14,865.    

Palace: Speroni, Butterfield, Hudson (c), Hill, Lawrence,Songo'o (Scannell 57), Derry, Watson (Martin 69), Soares, Scowcroft, Morrison (Fletcher 90+1).

Subs: Fletcher, Freedman, Hills.

Goals: Morrison (37), Scannell (90) 

Sheffield Wednesday: Grant, Hinds, Whelan, Tudgay, O'Brien, Watson (c), Simek (Bullen 27), J Johnson, Small, M Johnson, Spurr.

Subs: Lunt, Esajas, Beevers, Folly.

Goal: Hinds (10)

Referee: Mr Grant Hegley.

Assistant Referees: Mr D Buck & Mr J Pearce. Fourth Official: Mr D Margetts.