Boston is eliminated from first place.

To show that Boston is eliminated from first place, we start with the current conference standings:
            Team	W	L	GL	PCT	GB
       Cleveland	64	18	0	0.780	0.0
          Boston	61	21	0	0.744	3.0
        New York	51	31	0	0.622	13.0
         Indiana	50	32	0	0.610	14.0
       Milwaukee	48	34	0	0.585	16.0
         Detroit	44	38	0	0.537	20.0
         Orlando	41	41	0	0.500	23.0
         Atlanta	40	42	0	0.488	24.0
         Chicago	39	43	0	0.476	25.0
           Miami	37	45	0	0.451	27.0
         Toronto	30	52	0	0.366	34.0
        Brooklyn	26	56	0	0.317	38.0
    Philadelphia	24	58	0	0.293	40.0
       Charlotte	19	63	0	0.232	45.0
      Washington	18	64	0	0.220	46.0
           Total	592	638	0

Boston can finish the season with at most 61 + 0 = 61 wins and will finish the season behind the following teams:
Cleveland has already won 64 games.