The 35-over match was the culmination of a nationwide contest involving 900 schools organised by the English Schools Cricket Association.
The competition is sponsored by soft drinks company Calypso and the Government's Sportsmatch scheme.
Both schools have a tradition of sporting excellence. Lancaster royal, a selective grant-maintained boys' school, also excels at rowing, swimming and rugby. England cricket star Ben Hollioake played in the Millfield First X1 in 1990-91 and David Graveney, chairman of the England selectors, was captain in 1966.
In their 35 overs, Lancaster royal made 122 for 8. Millfield had to struggle for their first wicket which fell at 49. James Hildreth finished with bowling figures a Test player would envy - seven overs, six maidens, one run for one wicket. He bats at number 5, but didn't get the chance. Could he be a future all-rounder?
After lunch star guest Chris Silverwood, the Yorkshire and England bowler, strolled out to watch. He's a product of the local Garforth comprehensive and the Yorkshire Cricket Academy. He was impressed with the confidence of the youngsters playing their first match on a famous ground: "I was scared stiff."
At 4pm the score reached 100 for two for Millfield, Shaun Higgins and Alan Parker, two teachers from Lancaster Royal watched the match slip away. "It's been a marvellous experience. The boys must remember that they've never lost a game in two years and they're playing the strongest team around," said Mr Higgins.
Millfield won by eight wickets but both schools were praised by the two umpires, veterans of the East Riding Umpires Association. The umpires commented on the intelligent field placings and tactics.
Joe Becher, the diminutive Millfield captain, said: "We could've done with a better pitch. Have you seen the Test wicket? I wouldn't like to face Devon (Malcolm) on that."