Oval Invincibles 138 for 7 (Cox 51, T Curran 38*) tied with Welsh Fire 138 for 6 (Clarke 69*, Atkinson 3-26)
After winning the toss and having chosen to bat, Welsh Fire got off to a fast start as Clarke and Luke Wells put on 32 from 15 balls. But Atkinson began to turn the tide with three wickets from his first ten balls, including Fire captain Tom Abell, who was caught behind for a duck, as the score slipped to 43 for 4.
David Willey helped Clarke launch a recovery before he fell to Zak Chappell for 13, that being the only reward for the seamer who conceded only 15 from his 20 balls.
Green gave Clarke strong support with 25 off 16 balls including two sixes. Clarke’s excellent partnership with Green continued as he reached his half-century from 39 balls by thumping Chappell to the cover boundary.
Tom Curran, who took 2 for 27, ended the partnership of 58 from 36 balls as Green was caught at deep midwicket as Fire recovered well to finish the innings on 138 for 6.
Fire struck with the first ball of the home side’s reply with Jason Roy caught at gully off Shaheen Shah Afridi. The visitors might have also removed Will Jacks early on when he swung Willey to deep square leg but Green fumbled the chance as the ball went over the boundary for four.
Cox cut Willey for four having already driven Afridi twice to the cover fence and continued to thrive in the powerplay as he lifted David Payne over midwicket for a maximum.
Payne thought he had taken revenge later in the set when Cox appeared to be caught at third by Glenn Phillips but a decision review showed that the ball bounced first. Cox almost had another close call soon afterwards edging Haris Rauf just past the diving Clarke for four.
Cox dominated the partnership of 58 from 39 balls which ended as Jacks was caught at long-off with Green making amends for his earlier mistake.
Having reached his half century from 39 balls, Cox could only add one more before he was brilliantly caught by Green on the boundary, as the fielder palmed the ball back and kept his balance to complete the catch.
Green then took two wickets in five balls with Sam Curran and Heinrich Klaasen both caught in the deep to put pressure back on the home side.
With Oval needing 13 from five, Curran smashed a huge six off Payne that flew out of the stadium, before his final-ball athleticism snatched a tie.