Crouch scuffed England in front after four minutes and poached a rebound after 74 while Shaun-Wright Phillips, another player hoping to catch the eye of coach Fabio Capello, fired England's second on the hour.
Capello made six changes to the side that lost to Ukraine on Saturday, England's first competitive defeat under the Italian, with Crouch and Aston Villa's Gabriel Agbonlahor paired up front in the absence of Wayne Rooney and Emile Heskey.
While England were laboured at times, Crouch at least did his prospects of a place on the plane to South Africa no harm as he took his England tally to 18 goals in 35 appearances.
A bearded David Beckham, whose 30-minute cameo in the second half surprisingly earned him the man of the match award, earned his 115th England cap.
Wembley's ear-numbing sound system did its best to crank up some pre-match atmosphere for a match that was effectively a glorified friendly with England already assured top spot and Belarus long since out of the running.
Despite thousands of unoccupied red seats, Crouch raised the decibel level when he got the final touch to Agbonlahor's low cross after the striker had been released by Gareth Barry.
That was as good as it got though for England in the first half as they were frustrated by Belarus who knocked the ball around smoothly without showing much adventure.
Wright-Phillips, who was struggling to make any impact, looked likely to make way for the touchline prowling Beckham in the 60th minute but it was his fellow winger Aaron Lennon who was hauled off and Wright-Phillips made the most of his luck.
Picked out by Beckham's short corner, the Manchester City player jinked inside a defender and planted a low shot inside the post of Belarus keeper Yury Zhevnov.
With thoughts already turning to the coming months when players will jockey for spots in Capello's squad, Crouch was on hand to slot past Zhevnov who could not hold substitute Carlton Cole's 75th-minute drive.
England keeper Ben Foster, in for David James, made one world class save from Sergei Omelyanchuk while James Milner struck the woodwork late on for England.
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