With 30 minutes left at Selhurst Park, Crystal Palace and Sam Allardyce were facing embarrassment on an epic scale. 1-0 down to League One Bolton Wanderers, heading out of the FA Cup, extending to six their winless run under the new manager, plumbing a new depth beyond even what was reached in the final flails of the Alan Pardew era.

And then Christian Benteke came off the bench, scored two emphatic goals and Palace won 2-1. Suddenly everything looks different. Allardyce has his first win as Palace manager, relieving plenty of pressure that was gathering here. Saturday’s home game against Everton does not look as intimidating as it did before. Palace are into the fourth round of the FA Cup, and even if they do lose here to Manchester City, which is far from certain, it would be very different from losing here to Bolton.

This was not an impressive Palace performance but it was never going to be. What it showed is that without Benteke they are hopeless and heading towards the Championship. With Benteke, though, there is still hope.

Sam Allardyce met his former club for the second time in a fortnight (Getty)

Of course Allardyce took this game fairly seriously, and even with his very best players, Jason Puncheon, Christian Benteke and Yohan Cabaye on the bench, Palace still had enough firepower to ask serious questions of Bolton. Loic Remy made just his second start for Palace and Sulley Kaikai his first, in behind Remy, after years of loan spells.

Kaikai was recalled from a loan spell at Brentford earlier this month and he set about Bolton here, trying to prove to Allardyce that he is worthy of a place in his team. Given Palace’s obvious problems creating and scoring, and given Wilfried Zaha’s absence at the Africa Cup of Nations, why shouldn’t he?

After just 10 minutes Kaikai shot wide when released by Chung-young Lee. The next time Lee pulled one back for Kaikai, floating in the box, he skewed the ball over. But he continued to find space and to threaten. He earned a free-kick on the edge of the box, which he curled just wide, and fired another one into the stands. Palace did get the ball into the net, but it came off Joe Ledely’s hand. The goal was disallowed and he was booked.

Henry struck shortly after half-time to put the League One side in front (Getty)

Bolton did not exactly come to dominate Palace, but why should they, and they did carry a threat on the break. Josh Vela fizzed a shot just wide, and David Wheater volleyed over, two warnings to Allardyce that bad can always get worse.

Bad did indeed get worse, just three minutes after the restart. Palace failed to clear a loose ball and it fell to James Henry on the edge of the box. With no obvious other option on, he swung a left boot through it, and the ball flew up, over Julian Speroni and into the far top corner of the net.

Humiliation was staring Palace in the face and it prompted them into some brisker play. Joe Ward and Andros Townsend started to fire balls into the box but with only Remy up front, a good finisher but not exactly a target man, they did not cause any problems.

Christian Benteke rose to equalise after being introduced as a substitute (Getty)

Allardyce knew that it was time for reinforcements, and on the hour mark he brought on £40million worth of substitutes to get Palace back into the game. With Benteke up front and Puncheon in midfield Palace had more zip, while James Tomkins came on to sure up the defence.

Sure enough, it worked. Just five minutes after coming on, Benteke powered in an equaliser. Mathieu Flamini had the ball on the right and clipped a clever cross into the box. Benteke leaped and thumped his header into the net. It was a goal that, of all Palace’s players, only he could have scored.

His second goal, the winner, was even better, and stood out more for not being a typical Benteke goal. Andros Townsend broke down the left and pulled a cross back to the edge of the box. Benteke, with his back to goal, controlled the ball sharply and spun. Before the Bolton defence could adjust, he fired the ball into the bottom corner. It was a goal of £27m quality, and the appropriate difference between the two teams.

From there Palace saw out the game fairly easily, although Zach Clough nearly gave them a real scare at the near post. They can look forward to welcoming Manchester City here, reflect on a long-awaited win, even if took a big money signing to deliver it.

Crystal Palace (4-2-3-1): Speroni; Ward, Kelly, Delaney (Tomkins 62), Fryers; Flamini, Ledley (Puncheon 63); Lee, Kaikai, Townsend; Remy (Benteke 62).

Subs not used: Cabaye, Hennessey, Husin, Phillips.

Bolton Wanderers (4-4-1-1): Alnwick; Wilson, Wheater, Beevers, Taylor; Henry (Taylor 89), Thorpe, Spearing, Clough (Clayton 88); Vela; Madine (Proctor 78).

Subs not used: Moxey, Derik, Trotter, Turner.

Referee: Stuart Attwell