ST. LOUIS (AP) - Brad Thompson called it a ''waterfall effect.''

A St. Louis Cardinals' bullpen minus its closer and featuring three rookies was virtually untouchable throughout the postseason until Game 4 of the NLCS. Suddenly, relief pitchers who had allowed only one run in 20 2-3 innings were unable to get outs.

Thompson retired only one of five batters and gave up a three-run, go-ahead home run to Carlos Delgado in the fifth that triggered the Mets' mid-game explosion in a 12-5 victory on Sunday night that evened the NLCS at two games apiece.

Josh Hancock faced five batters in the sixth and got none of them out. All of them ended up scoring. Hancock, who had responsible for the only postseason run, has an astronomical 162.00 ERA in one-third of an inning.

Relievers who had to adjust to altered roles after Jason Isringhausen 's season-ending hip surgery in September said they'd adjust to getting smacked around, too.

''Forget about it, deal with it, and come to the park tomorrow fresh, knowing the phone can ring again and I can go in there at any time,'' Hancock said. ''It's not like we forgot how to do it.''

Johnson, who allowed Carlos Beltran 's second homer of the game in the seventh, reasoned that all of the offense amounted to only one loss.

''Whether it's 5-4 or 12-5, it's no different,'' Johnson said. ''You've got to give their guys credit, they've got a lot of good hitters over there, and sometimes they get the better of you.

''But tomorrow it's not going to happen.''

Rookie Anthony Reyes , making his first career postseason appearance, was not the problem. He struggled with his command and allowed homers to Carlos Beltran and David Wright in the third, but left after 88 pitches in four innings and with the game tied at 2.

''I kept the team in the game and tried to do the best I could with every pitch,'' Reyes said. ''But I threw too many pitches and I got forced out of there early.''

Then the roof caved in. The Mets blew the game open with three runs in the fifth and six more in the sixth and by the time the Cardinals' offense finally got to Oliver Perez it was too little and too late.

David Eckstein homered in the fifth off Perez, who was 3-13 with a 6.55 ERA this year for the Pirates and Mets, and Jim Edmonds and Yadier Molina added two more homers in the sixth.

Carlos Delgado hit a three-run homer in the fifth and a two-run double in the sixth off right-handed relievers, victimizing Thompson in the fifth and Hancock in the sixth. La Russa thought they would fare just as well as his two lefties in the bullpen, Johnson and Randy Flores .

''Both of those right-handers have been effective against left-handed hitters and that's a lot of game to pitch,'' La Russa said. ''They can get all of those guys out making good pitches.''

Entering the game, it appeared that the Mets' bullpen was the vulnerable one, given that starters the previous two games totaled five innings.

Reyes was the first rookie to start a postseason game since Rick Ankiel in 2000. Unlike Ankiel, who became the first pitcher since 1890 to throw five wild pitches in one inning and now is a minor league outfielder in the Cardinals' system, Reyes didn't allow the occasion to overwhelm him.

''I though the handled himself very well,'' La Russa said.

Reyes was La Russa's choice for the fourth starting spot over wildly inconsistent Jason Marquis , who had a 6.02 ERA and was left off the NLCS roster. He didn't let the occasion overwhelm him.

''I tried to treat it just like another day, and it definitely worked,'' Reyes said. ''I wasn't too nervous and I felt pretty good.

''I thought that helped me out a little bit.''