Padre Lead Gets Lost In Smoke : Baseball: Relief staff cannot keep Montreal Expos from sweeping series with a 6-3 victory.

The volatile group that passes for the Padre bullpen made Mother’s Day a grand one for the Montreal Expos.

After seven innings of the series finale at San Diego Jack Murphy Stadium, Bruce Hurst had a 6-3 lead and was closing in on his fifth victory without a defeat. But when the first two batters in the eighth reached base, Manager Greg Riddoch called for help, and the game went up in flames immediately.

First Mike Maddux, then Rich Rodriguez and finally John Costello tried to bring relief. Their efforts set off a four-run explosion that led to an 8-6 defeat. After Costello gave up a run in the ninth, Steve Rosenberg struck out the only man he faced.

The outcome gave the Expos a three-game sweep. The Padres now have lost five consecutive games in a run of futility that has dumped them from first place to fourth in the National League West--they are below .500 for the first time this season--and the Expos have won six consecutive games.

Watching the Padres blow a late-inning lead for the second time in three games was cause for some serious booing by the paid crowd of 17,202.

Riddoch was as charitable after beating a path between the dugout and the mound in search of a relief pitcher.

“I thought we had that one,” he said. “We just didn’t get it done pitchers-wise.”

Pitching coach Mike Roarke felt especially bad for Rodriguez, who wound up as the losing pitcher. Rodriguez had been the Padres’ one effective middle reliever of late. This time he walked the first two batters he faced and had 2-0 on the third before being yanked.

“Rich had been coming in and getting big outs for us,” Roarke said. “Unfortunately, when you’re in a slump like this, every mistake you make is magnified.”

By going four for five with three runs batted in Sunday, Tim Wallach made it eight for 11 with 11 RBI on the last two Mother’s Days. He hit two three-run homers here a year ago.

“I just think I hit better here in daytime games,” Wallach said. “I hit better in daylight, period.”

Wallach was retired for the only time all day in the decisive eighth, but that didn’t prevent him from driving in his third run. After Marquis Grissom had walked and Ivan Calderon had singled to chase Hurst, Wallach hit a ground ball against Maddux that brought in a run and cut the Padres’ lead to 6-4.

When Andres Galarraga’s double brought the Expos within one, Rodriguez was summoned. When Rodriguez couldn’t find the plate, Costello entered and promptly served up a game-tying single to Spike Owen. Nelson Santovenia then broke the tie with a fielder-s choice that was almost a inning-ending double play.

Hurst threw the fairly modest total of 94 pitches, 60 of them strikes, but Riddoch said he seemed to be growing weary.

Asked if he was upset about being taken out, Hurst said, “I never question the manager.”

Asked if he was running out of gas, he said, “I’ve never been one to say I’m tired. I needed to get one out of the first two guys out, and I couldn’t do it.”

The Padres were held to six hits by four Expo pitchers, and used just five to build a lead they could not keep. Among the hits was another home run by Fred McGriff, who now has four in four games.