Warwicks won the toss on a rain affected day and put the home side into bat.
With Jack Rudolph in fine form as always, the home side put on 76 for the first wicket which saw Gale caught by Clarke off the bowling of Keith Barker.
Lyth followed with the score on 91, caught by Maddy to give Ant Botha a wicket and shortly afterward, McGrath was caught by Wicketkeeper Richard Johnson.
Rudolph and Gerard Brophy put on 99 for the fourth wicket and in the 37th over, Rudolph was finally run out for 106 for 145 balls to see Yorkshire end their innings on 257-7.
With Varun Chopra in for Jon Trott, Warwicks had put on 65 before Neil Carter was trapped lbw after making 40. Chopra and Barker added 52 before the later was caught behind.
Ian Bell came in and hit 57 before Troughton went for two. Chopra was finally out for 76 to see Warwicks 216-5.
Darren Maddy and Rikki Clarke took over. They added 34 before Clarke was bowled but Maddy and Botha added the final ten runs to give Warwicks a four wicket victory and a place in the final.