WORCESTER, April 19--Left-hander Bob Kessler, a pitcher with good control and a tantalizing delivery, gave a strong Holy Cross team fits of frustration here yesterday as he pitched a smooth 3-0 shut-out to give the varsity one of its most important wins of the season.

The difference in the game was in the fielding as the Crimson played errorless ball behind its pitcher. Whenever the Crusaders began to hit Kessler hard, time and again a varsity fielder would choke off the rally with a fine defensive play. Holy Cross could not give their equally effective pitcher, Don Cote, such support, as they erred three times.

The Crimson jumped into the lead in the top half of the first inning when Bob Cleary walked and scored on Babe Simourian's towering triple to left center. John Getch then drove Simourian in with an infield out to give the Crimson a lead they never relinquished.

Both teams went scoreless up until the sixth inning, when the varsity added one vital insurance run. Dick Fisher led off with a sharp single to left and moved to second on Matt Botsford's sacrifice bunt. After Bob Hastings had grounded out, Catcher Bing Crosby then hit a 3 and 0 pitch for a double down the left field line to drive in Fisher. Fisher and Crosby each garnered two of the Crimson's six hits.

The Crusader's chief threat came in the last of the ninth when Kessler weakened and allowed a single and a walk. One pitch later he was out of the jam, as Hastings, Cleary, and Simourian engineered a quick double play to put out the fire.

Yesterday's game saw two important changes in the varsity lineup as Coach Norm Shepard endeavored to give the team more hitting strength. John Getch moved to right field and the clean-up slot in the batting order, while Matt Botsford took over third base from light-hitting Stu Lavine.