Australian all-rounder Ian Harvey marked his return to Yorkshire's side after injury with a stunning unbeaten century as Lancashire were crushed by eight wickets with 13 balls to spare in the Twenty-20 Roses clash at Headingley last night.

But Yorkshire's triumph came at a heavy price because captain Craig White suffered a knee injury while fielding early in the game and he will now miss the semi-final of the Cheltenham and Gloucester Trophy at Bristol on Saturday.

A deeply frustrated White had to hobble around on crutches with his left knee locked after retiring hurt and he will have a scan today, but he looks certain to be out for several weeks if he has damaged a cartilage.

White only returned to action at the weekend following a hamstring strain and he was looking forward to helping Yorkshire overcome the last hurdle on their way to Lord's.

"I am absolutely gutted to pick up this injury but I will have to wait and see what the scan reveals before I know how long I will be sidelined," he said.

Yorkshire's rousing victory keeps them in with a shout of reaching the quarter-finals but the ease with which it was obtained could not be envisaged while Andy Flintoff was blasting his way to 85 off 48 balls after opening the Lancashire innings.

It was with Lancashire's score on 38 for one in the fourth over that Flintoff struck a delivery from Tim Bresnan high over mid-on and White hurt his knee pedalling backwards in a futile attempt to catch the ball.

Flintoff, who had opened his account with five consecutive boundaries, was held at long off by substitute fielder Chris Silverwood on 42 but only then did it become apparent that Steve Kirby had bowled a no-ball.

Kirby soaked up much of the punishment from Flintoff and the paceman's four overs cost 60 runs, the most expensive spell by a Yorkshire bowler in the competition.

There was no containing Flintoff until off-spinner Andy Gray came on and in his first over held on to a stinging return catch. Gray went on to capture three for 18 off 3.1 overs to register his team's best bowling figures.

Harvey, playing his first game in two months after recovering from a torn hamstring, also bowled with splendid variation to claim two for 30, but it was with the bat that he had the 11,600 crowd roaring their approval.

Opening the innings, Harvey proved to be even more dynamic than Flintoff and he slammed four consecutive boundaries in Glen Chapple's first over, all authentic strokes to different parts of the ground.

Harvey drove Dominic Cork over long off for six to rush him to 42 from just 17 balls and his half-century came with a straight six off Sajid Mahmood. Fellow Australian Phil Jaques cracked a big six off Carl Hooper and the second-wicket pair had taken their stand to 108 in 11 overs when Jaques was caught by substitute fielder John Wood for 39 from 32 balls.

There was simply no stopping Harvey, who equalled Flintoff's 85 off three fewer balls, and after notching Yorkshire's first Twenty-20 century he finished the game with a boundary to end unbeaten on 108 from just 59 balls with 16 fours and two sixes. Yorkshire meet Durham at Riverside today after which they will know if they have made it to next Monday's quarter-finals.