Mal Acosta of Hayward, Calif., who said two days ago that no bowler would catch him in the $110,000 Fair Lanes Open, made good on his promise yesterday at Fair Lanes Capital Plaza in Hyattsville, defeating Tommy Hudson of Akron, Ohio, 229-189, in the final bowl-off to win the $15,000 first prize.

After throwing strikes in the first and second frames of the nationally televised contest, Acosta rolled spares in the next two frames and had an open frame in the fifth with the No. 10 pin left standing.

At that point Hudson, winner of the 1977 Fair Lanes Open, led, 103-92.

"There are only 10 frames, and I knew I had to make a move so I did it then," said Acosta, 29, the top seed in yesterday's bowl-off. "I moved my feet two boards to the left and my eyes one board to the left, and that worked."

Acosta threw strikes on his next five balls and got seven pins on his last to beat Hudson, the No. 2 seed, who faltered in the final frames. Hudson got to the final round by defeating Larry Laub of Santa Rosa, Calif., 214-192.

"I was just too nervous out there," said Hudson, who last won a singles title in 1979 in Las Vegas. "I haven't won in a while, and I beat myself. The lanes were all right, but, when I get nervous, I throw too soft and I can't get any speed on the ball."

Under the format for yesterday's bowl-off, the top five bowlers after three days of qualifying and match competition faced each other in a four-game seeded match with the loser being eliminated and the winner playing the bowler seeded ahead of him.

In the first game of the afternoon, Tom Laskow of Commack, N.Y., (seeded fifth) defeated Kent Wagner of Allentown, Pa., (seeded No. 4) 213-184. Laskow then lost to Laub, 214-162. Laub, winner of the 1979 Fair Lanes Open, dropped the next game to Hudson. Hudson will get $8,000 in prize money, Laub $6,000, Laskow $5,000 and Wagner $4,000.

Laub bowled a strong game his first time out, but the erratic play that has plagued him throughout the tournament recurred against Hudson. "I was lucky to get that far," Laub said. "My game has been off all year, but I've been working on it. I did at least get a 213 in my first game."

Acosta, who bowled a perfect game in the first round of match competition Thursday night, has been on the Professional Bowlers Association Tour five years and was 19th in earnings last year with $48,815.

He bowled in the 1980 and 1981 Fair Lanes Open but failed to win money. The $15,000 he won yesterday puts his 1982 earnings at $33,210. CAPTION: Picture, Mal Acosta, nears victory in his final contest with Tommy Hudson in the Fair Lanes Open at the Capital Plaza and, he roots home a strike. Acosta's victory was worth $15,000. Photos by Joel Richardson--The Washington Post