The home side's 202-9 total looked challenging on a wicket that had a bit to offer the bowlers.
But overseas ace Murphy took the game away from the home side with a devastating century off just 39 deliveries. Murphy took just 18 balls to reach his fifty and was bowled by spinner Nadeem Khan one ball after notching his ton with one of a number of huge sixes.


Teenager Luke Patel and captain John Randerson then knocked off the runs at a more sedate pace to get Cas home with 18 overs in the bank. Patel made 31 not out and Randerson an unbeaten 45.



Chris Young (3-39) and young off-spinner Josh Wheatley (2-30) were the pick of the visitors' bowlers as Sheffield lost wickets at regular intervals. Number nine Andy Simpson hit 38 off only 30 deliveries to finish Sheffield's innings with a flourish.
Castleford went down by seven wickets at unbeaten Barnsley on Saturday - the first league defeat of the season for Randerson's men.


After losing Murphy cheaply it became a struggle for Cas, who were all out for 167 in 54.1 overs.
Randerson top-scored with 37 from 75 balls, Patel and Chavez Younes offered most of the support and there was late resistance down the order from Will Hodson and Gary O'Neill.


But Barnsley, watched by long-time supporter Sir Dickie Bird, coasted home for the loss of only three wickets, with Simon Widdup hitting a half-century, Alex Morris cracking 42 and Steve Nuttall making 34 not out to earn the South Yorkshiremen a fourth straight win.
Randerson took 2-36 for the home team, with O'Neill taking the other wicket to fall.