Ring the bell for Round 6.In the...

Ring the bell for Round 6.

In the furious fight for pro basketball’s world championship, with the challengers ahead but on shaky legs, the Lakers will go for a knockout in their best-of-seven series against the Boston Celtics on Sunday.

Down by a game and backed against the ropes, the stubborn Celts are likely to come out swinging . . . uh, battling at the Forum on CBS at 12:30 p.m. (2)(8).

At the top of this weekend’s busy baseball list are the California Angels, as Gene Mauch’s men try to climb the American League’s Western Division ladder against the Kansas City Royals on the road. KTLA Channel 5 carries the action starting today at 5 p.m. and Sunday at 11:30 a.m. (5).

Earlier today, NBC has the Chicago Cubs-St. Louis Cardinals game from Busch Stadium, beginning at 11:15 a.m. (4)(36)(39), with the teams going at it again Sunday at 11:15 a.m. on WGN cable.

Meanwhile, cable TV viewers also can catch the Atlanta Braves vs. Cincinnati Reds today at 4 p.m. on WTBS and Sunday at 11:05 a.m., while WOR offers the New York Mets vs. Pittsburgh Pirates today at 4 p.m. and Sunday at 10:30 a.m.

If golf is your game, then point a TV dial in the direction of CBS. The network will cover the final rounds of the Westchester Classic today at 3 p.m. and Sunday at 10 a.m. (2) (8).

Another best bet for golfers is an ABC preview of the U.S. Open with Jack Nicklaus. Reported by Nicklaus and Jack Whitaker, the half-hour program arrives today at 4 p.m. (7)(3)(42).

One other program of note is Sunday’s “Survival of the Fittest” on NBC’s “SportsWorld.” The telecast from Australia features a typically grueling four-event competition that tests speed, strength and stamina. It airs at 1:30 p.m. (36)(39) and 2:30 p.m. (4).