The Rochester net was completely open early in the first half yesterday when the Diplomats' Tony Crescitelli booted the ball over the crossbar from close range.

Many in the RFK Stadium crowd of 15,307 chanted "Lu-na" in heated demand that young Argentine striker Mario Luna take Crescitelli's place. "I felt like I should shoot myself," Crescitelli said.

Luna eventually would replace Crescitelli, but the only shooting by the 23-year-old U.S. Olympian was aimed at the Rochester net. Crescitelli scored twice, 96 seconds apart, and sent the Diplomats ahead to stay as they whipped the visiting Lancers, 4-2, for their fourth straight victory.

Rochester was losing for the fifth straight time and this contest did not figure to be close. But the Diplomats have a way of permitting weak teams to stay in contention and it was not until Don Droege's goal with six seconds left that Washington Coach Gordon Bradley could breathe easily in the 88-degree heat.

"It wasn't a good game," Bradley said. "There were a lot of mistakes by both teams. Early in the season it was a game we might have lost, but today we showed some character and stayed with it."

After Crescitelli failed to convert his early grand opportunity, Carmine Marcantonio gave the ball away at the other end and it wound up in the Washington net.

Rochester's Branko Segota stole the ball and quickly fired from 20 yards. Washington goalie Dragan Radovich, startled by the sudden change of possession, touched the ball but could not control it.

Five minutes later the Diplomats were in front. First Crescitelli took a center from Tommy O'Hara, turned and drilled the ball into the left corner. Then Johan Cruyff delivered a long pass into the box, Crescitelli outfought defender Laszlo Harsanyi and the Dip striker kicked the ball past diving goalie Emanuel Schwartz.

"To make such a bad play at the beginning of the game, I thought, 'What am I going to do?'" Crescitelli said. "I was sure I was coming out of the game. Usually when you miss your first chance to score, you have a letdown and don't get any more. This time I got more chances, thank God."

Crescitelli was knocked down in the penalty area by Demir Sutevski, bodyblock style, without a call or he might have had a hat trick in just five minutes. But he had departed before Alan Green finally gave Washington a 3-1 lead with 18:46 left in the game.

The Lancers were yapping about an alleged hand ball in the Washington penalty area when Radovich booted the ball downfield. Green outfought defender Jim Pollihan and kicked one just under the crossbar. It was Green's 20th goal, but they have not been coming easily lately.

In fact, Green thought he had scored late in the first half, when his long shot was deflected by Schwartz and, according to the Diplomats, struck the stanchion holding the nets before rebounding out. Referee Gino D'Ippolito accepted linesman Derek Davis' ruling that it struck the post.

"I thought it hit the stanchion, everybody did," Green said. "I was glad to get that goal later. I've been trying everything, getting good positions, but I couldn't hit the back of the net. I went 10 games without a goal last year. I don't need that again."

With 15:34 to play, Rochester sub Mike Stojanovic broke away from two defenders, Droege and Bob Iarusci, to score from close range. But the Lancers had few chances to pull even before Droege converted a header from Cruyff just before the finish.

Rochester Coach Alex Perolli continued the NASL losers' pattern of complaining about the officiating. He was given a yellow card when he left the bench area to argue late in the game.

With the Lancers deep in last place in the National East, Perolli does have problems. Segota, Rochester's leading scorer, was suspended after the first Washington game for throwing his jersey at Perolli when he was removed from the game. Yesterday, after Radovich beat Segota to a Lancer pass, Perolli berated Segota verbally. The striker responded with an obscene gesture.

Luna replaced Crescitelli midway through the second half, after Crescitelli had been kicked in the right thigh. It was not serious, but as Bradley said, "Tony did so much work, I figured he'd given what he had to give."

Crescitelli, who was out almost two months with a muscle pull earlier in the season, said, "I felt pain and I figured it would be best to give Luna a chance. I was out a long time before because I was stubborn and stayed in a game when I was hurt. I've learned my lesson."

The Diplomats firmly grasped second place in the National East, nine points ahead of Toronto and 27 in front of the Lancers.