pulled off the biggest upset of the BLTC Invitational tennis tournament yesterday at Coral Beach Club when she captured the women's 40s singles title with a 6-3, 3-6, 6-1 victory over top-seeded American Yvonne van Nostrand.

The match took an hour and 47 minutes and was one of the week-long event's most unusual as the van Nostrand failed to hold her service until the 12th game, by which time she was a set down, but leading 2-1 in the second.

In fact neither player was able to find any rhythm until the eighth game when Butterfield held for the first time then broke her opponent to seize the opening set.

After finally holding though, van Nostrand broke and then held for a 5-1 advantage to level the match.

Just as the first two, the final set began with consecutive breaks, but once van Nostrand double-faulted for the fourth time in the third game, Butterfield reeled off five straight games for the title, her first in this division.

"She (Butterfield) really played well,'' said an exhausted van Nostrand afterwards. "She just played a terrific game and is more fit than I am.'' Butterfield did not feel that either player had performed to their potential in the first set.

"Neither of us could hold our serve,'' she said. "I really didn't think I was going to win it, but then she changed her game and I was able to get on top and she made a couple of unforced errors and there I was, the winner.

"I'm really pleased.'' The day's lone other final witnessed the United States pair of King van Nostrand and Abbey Butler winning the men's 55 crown with a comfortable 6-3, 6-1 triumph over fellow countrymen Bob Brown and Gene Whitman.

Surprising was the ease with which top men's doubles pair Stuart Smith and Brian Way disposed of the challenge presented by Andre Dupre and Butler, as the former required less than an hour to win in straight sets, 6-2, 6-3.

In the mixed doubles, Barbara Laporte and Way advanced to the final, beating Dupre and Morley Miller 6-4, 6-2 creating a battle against Butterfield and Mike Curry, who ousted Gretchen Devlin and John Moore 6-0, 6-1.