Warwickshire beat Yorkshire by three wickets to go top of their CB Pro 40 group.
Warwicks won the toss at Edgbaston and put the visitors into bat.
In a rain affected innings, Yorkshire had Andrew Gale score 76 and Adam Lyth hit four sixes in a knock of 69 as Yorks ended on 213-7 after 34 overs.
Under Duckworth/Lewis, this meant Warwicks needed 238 to win. Will Porterfield went for nineteen and Chopra for 34 before Jim Troughton and Tim Ambrose came in.
Troughton made 61 and Ambrose made 61 to leave Warwicks needing 48 from 30 balls.
With three overs left, three wickets in hand and Stefan Piolet and Paul Best who had taken three wickets at the crease, Warwicks still needed 34.
Two sixes and a four from Piolet saw Warwicks needing six from the final over.
That was attained and Warwicks won by three wickets with four balls remaining.