Lyth struck 54 not out from 49 balls with five fours as Yorkshire overhauled their opponents’ total of 129-7 with 3.1 overs to spare.
Lyth – one of six Yorkshire players in the England squad along with Joe Root, Gary Ballance, Liam Plunkett, Adil Rashid and Jonny Bairstow – was in fine form, sharing an opening stand of 59 with Andrew Hodd, who made the second-top score of 28.
Yorkshire play Lancashire in their semi-final of the Emirates T20, which is structured on the same lines as England’s Twenty20 Finals Day, with Sussex playing MCC in the other semi-final.
On Sunday, Yorkshire start their four-day Champion County game against MCC in Abu Dhabi, which marks the beginning of the first-class season.
Rohit Sharma led defending champions India into the semi-finals of the World Cup with a 109-run victory over Bangladesh at the MCG.
Sharma’s imperious 137 off 126 deliveries provided the backbone of India’s innings as they made 302-6.
With a big total to defend, it was then over to Umesh Yadav, who took 4-31 to restrict Bangladesh, who were all out for 193 as India claimed a seventh win in a row.