Tom Splaine of Montgomery Village came back from a two-hole deficit to win the final six holes and defeat John Haddock of Penderbrook, 4 and 3, yesterday to capture the Marvin (Bubby) Worsham junior championship at Bethesda Country Club.

"I feel good," said Splaine, a 17-year-old senior at Gaithersburg High School. "I'm where I was before. The feeling of victory is back again."

Since winning the 1979 Montgomery County High School title as a sophomore, Splaine had failed to match that success. In the last two years he has finished 24th and 22nd in the Maryland state tournament.

Splaine had to hang on to keep within range of his opponent before winning the last three holes to defeat Haddock, 17, the Virginia state high school champion from Annandale.

The first two holes of the match quickly went to Haddock, who parred No. 1 after a precision chip from the right bunker and sank an eight-foot par putt on No. 2.

Haddock applied heavy pressure throughout the front nine. Splaine halved both the eighth and ninth holes with tough putts.

The two holes started Splaine's rally. He stroked in a seven-footer for par on No. 8 after sending a 55-footer past the hole and followed with a nine-footer for par on the ninth. "I hit it better than him the entire round but he drained everything in sight," said Haddock.

From the 10th hole on, Splaine's game showed confidence. Splaine parred 10 and birdied 11 to tie the match, then had four pars to Haddock's four bogeys. The two shook hands on the 15th and Splaine caught a golf cart to the clubhouse to accept the trophy for "my biggest victory yet."

"We've never had such a reversal of form as fast as that one," tournament director Frank Emmet said of this 31st Worsham. The first event, in 1951, was won by Arnold Palmer.

Of this year's eight quarterfinalists, Splaine and Haddock were the only two juniors still in high school. Splaine defeated four collegians en route to his title.