Soriano moved into a tie for second place on the all-time leadoff homer list with Craig Biggio in a game that was stopped following a 58-minute delay before the bottom of the eighth after a barrage of lightning and rain. It also started 37 minutes late and was interrupted for four minutes after the fifth inning, but on this humid night, long drives were as constant as the raindrops.

"Theriot with a two-homer game -- how about that?" manager Lou Piniella said with a grin.

There was plenty to smile about even though Adrian Gonzalez hit two homers off Chicago's Ted Lilly (5-2), giving him 13 overall and at least one in three straight games. His two-run shot in the first put the Padres ahead 2-0, but the Cubs responded with three in the bottom half against Chris Young (2-2), sending San Diego to its 18th loss in 22 games and 10th straight on the road.

Soriano started the onslaught with his fourth leadoff homer this season and his 21st as a Cub, breaking a club record set by Jimmy Ryan in the 1800s when he drove the ball beyond the left-field bleachers. Theriot connected on the next pitch and added a solo shot in the fourth for his second career multihomer game. Soto, the NL rookie of the year last season, broke out with an RBI single in the first and two-run drive in the third -- his first homer.

That was enough for Lilly, who settled down and won his third straight start. The veteran left-hander allowed three runs and eight hits with seven strikeouts and no walks before leaving to cheers with one out in the seventh.

"Maybe because my pitches are so good they want to swing at the ball," Lilly said about the lack of walks. "I still feel like my command on both sides of the plate can improve."

Angel Guzman allowed a hit but got the final two outs in the seventh, and Carlos Marmol earned his third save in five chances despite allowing a run in the eighth.

Padres manager Bud Black was upset that the game got stopped but also said it's "a tough call" and he respects crew chief Tim Welke "immensely."

More unsettling was the performance by Young, who allowed six runs in four innings and is 0-2 in his last six outings. That left Padres starters 0-11 since Jake Peavy beat the New York Mets on April 16, and right from the start, there was trouble.

The good feeling Gonzalez created in the first disappeared as quickly as a ball sailing over the wall.

"I was just off," Young said. "Mechanically I wasn't very good. I had trouble finding my rhythm and against a lineup like that, it's hard to come out and not have your best stuff because it's a good lineup and they punish some bad pitches."

One big swing by Soriano and another by Theriot tied it.

The back-to-back homers to start were the first by the Cubs since April 27, 2000 at Houston and the first ever allowed by San Diego, according to the Elias Sports Bureau.

Soto, who raised his average from .175 to .193, then singled in Milton Bradley to give Chicago a 3-2 lead and made it 5-2 with that homer in the third.

Besides dropping the game, the Padres lost shortstop Luis Rodriguez to a sprained left ankle. He was injured rounding first following a single in the seventh and was lifted for a pinch runner.

X-rays were negative, but Rodriguez will likely be placed on the DL before Friday's game against Cincinnati.

Game notes
Cubs ace Carlos Zambrano threw a bullpen session on Wednesday and remained on track to make a rehab start this weekend. Zambrano went on the 15-day disabled list on May 4, a day after he strained his left hamstring trying to beat out a bunt. He is scheduled to pitch Saturday or Sunday in Clearwater, Fla., before starting against San Diego on May 22. ... 3B Aramis Ramirez said he's still feeling pain in his dislocated left shoulder and isn't sure when he'll return. He was injured on a backhand dive against Milwaukee on May 8 and went on the disabled list the following day. ... Rickey Henderson holds the major league record with 81 leadoff homers.