Veteran junior star Joe Walter, armed with the trusty one-iron he used for most of his tee shots, scored par four on the first extra hole and beat upset-minded Larry Rentz, 1 up, in the final of the 27th annual Marvin (Bubby) Worsham Memorial golf tournament yesterday at Bethesda Country Club.

Walter, 20, who plays No. 2 on the University of Georgia golf team, trailed for most of the match but settled down to even-par 5 on the back nine and overcame the long-hitting Rentz's two-up advantage.

Walter, who played much of his junior golf in this area although playing out of the Mt. Pleasant public course in Baltimore, was the clear favorite, having won the Dixie Amateur and finishing second in the Porter Cup this season.

The two shared medalist honors with 70 and easily reached the Worsham final.

Rentz, 18, pillar of Fairmont Heights' team and freshman to be at the University of Florida, was the nations junior representative in the National Long Driving contest prior to the 1976 PGA at Congressional.

He swung within himself yesterday and reduced some of Bethesda's 500-yard plus par-four holes to a drive and a wedge.

"I'll just try to keep the ball on the golf course," he said before the match.

Walter, who started with two bogeys, said his early troubles arose from his left side being dominated by his right, forcing a hook.

Rentz was steady early and took a two-up lead with par on the ninth hole.

Walter pulled within one hole with a birdie on the 517-yard 11th, getting down in two after two monstrous wood shots left him barely off the green.

Rentz scored a birdie two for a two-up lead at the 163-yard 13th. Solid as a rock on previous short putts, Rentz then missed a four-foot putt to lose the 14th hole that seemed to signal his doom.

He drove into the trees and lost the next two holes, enabling Walter to take his first lead of the match, one up, heading to 17.

Rentz won 17th with par to square the match and holed a testy downhill seven-footer to halve the 18th hole in par fours.

Walter hit the first extra hole with a 250-yard one-iron and a wedge. Rentz did the same with a driver and a 250-yard one-iron and a wedge. Rentz did the same with a driver and a wedge. Rentz rolled his delicate 20 foot, downhill birdie attempt, four feet past the hole and missed coming back, leaving Walter a short tap-in for par four and victory.

Walter said he used his one-iron off the tees because "on this course, a lot of holes require position off the tee. I didn't hit the ball too well today but it turned out all right," he said.