England's countdown to the World Cup in South Africa continued with victory against Mexico at Wembley.

Fabio Capello's reshaped side delivered a patchy - and at times unconvincing - performance as England finalise preparations for their opening World Cup encounter against the United States in Rustenburg on 12 June.

Ledley King marked his first England appearance for three years by heading them into an early lead and Peter Crouch kept up his outstanding international scoring record by scrambling home for his 21st goal in 38 appearances before the interval after Wayne Rooney saw his header turned on to the bar by Mexico keeper Oscar Perez.

Mexico took control in between those goals, with England keeper Robert Green enhancing his World Cup claims with a fine save from Carlos Vela, although he was powerless as Carlos Salcido struck the post from the edge of the area.

England's defence, disorganised and nervous, had led a charmed life and it was no surprise when Mexico pulled a goal back on the stroke of half time when Leighton Baines failed to complete a goal-line clearance and Guillermo Franco pounced.

Glen Johnson ended Mexico's bid to mount a revival when he produced a superb finish from 20 yards two minutes after the break, and that was effectively the end of England's anxious moments.

England now have one final friendly against Japan in Austria on Sunday before the squad is named and heads for South Africa, and Capello will still have questions to ponder before he puts his plans in place.

He will have been concerned by England's defensive vulnerability, but he was able to see injury-plagued Tottenham defender King complete 90 minutes and his worries will be placed in context by the knowledge he has Chelsea duo John Terry and Ashley Cole to recall.

Frank Lampard was also missed in central midfield, where the starting partnership of James Milner and the very disappointing Michael Carrick failed to fire.

Crouch bundled in England's second at Wembley

And, despite another goalscoring display from Crouch, it will be intriguing to see if Capello is tempted to use Rooney as a lone striker, supported by Steven Gerrard, against Japan. It is an option worth exploring.

Capello's side inevitably had an experimental appearance - and how it showed in a first period when England were inferior to Mexico and yet somehow established a lead by the interval.

They went ahead after 17 minutes when Mexico failed to deal with England's traditional strength from set pieces. Crouch rose to meet Steven Gerrard's corner and King was unmarked close in to glance a header past keeper Perez.

Rather than helping England settle to their task, the goal was simply the signal for Mexico to emphasise their superiority in possession and demonstrate a sharpness that exposed Capello's reshuffled rearguard.

Green did well to twice deny Arsenal forward Vela as he broke through the centre of England's defence, but he relied on the woodwork to come to his rescue on the half-hour when Salcido's shot hit the outside of the post with the keeper beaten.

England always had the edge in the aerial battles, however, and so it proved again as they doubled their lead after 35 minutes to produce a scoreline that was flattering in the extreme.

Johnson scored a fantastic third

Mexico keeper Perez did superbly to turn Rooney's header onto the bar when he met another Gerrard cross, but Crouch was able to use his height to bundle the rebound over the line.

The goal Mexico deserved for their enterprise came in first-half injury time - and was a perfect illustration of the defensive disorganisation that had plagued England in the first half.

King lost Rafael Marquez, and when Baines failed to clear convincingly on the line Franco scrambled the loose ball in to give Mexico some reward.

Capello made three changes for the start of the second half, with Jamie Carragher ending his England exile by replacing Rio Ferdinand, while Jermain Defoe and Joe Hart came on for Crouch and Green.

If Mexico's goal offered them hope of a recovery, it was quickly snuffed out in spectacular fashion as right-back Johnson showed his prowess as an attacking force after 47 minutes. He cut in from the right before curling a measured left-foot finish into the top corner.

Rooney had been having one of his quieter nights for England, but he almost added a fourth with eight minutes left. He lofted an effort towards goal with the Mexico keeper stranded out of position, but Francisco Javier Rodriguez was perfectly positioned on the line to clear the danger.

England suffered no further scares and took the applause from the Wembley crowd as they said farewell with a lap on honour in their last appearance on home turf before the big kick-off in South Africa .