Karnataka completed a historic treble at domestic level by emerging champions in the Vijay Hazare Trophy with a four-wicket win over Railways on Sunday. In yet another low-scoring affair at Eden Gardens, Kolkata, the Ranji and Irani Trophy champions Karnataka lost five wickets in 26 runs to be 47 for 5 in the 12th.However, sensible batting by youngsters Karun Nair who scored unbeaten 53 and Lokesh Rahul with 38 set up the chase with a 66-run partnership.Brief Scores:Railways: 157 in 47.4 overs Karnataka: 158 for 6 in 43 overs