It will long be remembered as the day staid Wimbledon turned into the Latin Quarter.

Even before victor Roscoe Tanner and vanquished Tim Gullikson had left the Center Court of the All England Lawn Tennis and Croquet Club following their opening match today, the clapping and chanting for Adriano Panatta had begun:

"Ah-dree-ah-no [clap-clap, clap-clap-clap] . . . Ah-dree-ah-no [clap-clap, clap-clap-clap-]."

The clusters of strong-lunged Italians who had waited in line since early morning, then made a dash for the standing room section on either side ofCenter Court as soon as the gates opened at noon, now were warming up with football-style cheers for their hero, the handsome Panatta.

When ItalyS favorite tennis player strode onto the hollowed court with his quarterfinal opponent, Belgian-born U.S. citizen Pat Dupre, and bowed to the royal box, there was none of the usual decorum.

Panatta's fans greeted him with upraised arms, flapping sweaters and towels, Italian flags and noisy encouragement. They turned the stately and usually hushed arena into a green echo chamber of the sort of admiration Panatta regularly gets when he plays at home in Rome.

Many of the cheerleaders were students, but there seemed to be a good cross-section of London's Italian population of 300,000. Most of them had been at Panatta's earlier matches, similarly exhorting him on at the outside courts.

"they come to London as waiters in Italian restaurants, and now they own the restaurants, so they can take the week off," said an Italian journalist, Gianni Clerici. "now the English work for them."

Silence came only in the long shadows of dusk, when DuPre came back from two sets to one down to win, 3-6, 6-4, 6-7, 6-4, 6-3.