If the Houston Astros don't unravel after their second straight beating in Riverfront Stadium, having lost tonight to the Cincinnati Reds, 7-4, then they are truly a team of amazing recuperative powers.

Every portent, every foreshadowing of the beginning of the end of a fine pennant race was at hand tonight as the Reds, who on July 4 trailed Houston by 10 games, pushed 1 1/2 games ahead of the plucky Astros in the National League West.

Every reason for the Reds' 42-23 resurgence since July 4 was on display, while the causes of Houston's depressing 29-33 record since that date also were apparent. The Astros would be best advised to forget these two nights' work, when their premier pitchers, J. R. Richard and Joe Niekro, were knocked out. If they can.

Most of the Reds' bright young names took part in this victory. Dave Collins and Ray Knight -- the .320 hitters who have replaced injured Ken Griffey and traded Pete Rose -- each had three hits. Pitcher Tommy Hume, one of new Manager John McNamara's reclamation projects from the arm-graveyard days of Sparky Anderson, won Tuesday's game and preserved the victory tonight for relief man Frank Pastore.

This game ended on a symbolic note that no one in the crowd of 42,035 possibly could have missed.

Cesar Geronimo made an absolutely breathtaking diving catch in right-center on a Craig Reynolds liner for the last out. The Reds' flychaser knew that the play was not absolutely essential to victory -- he just wanted to show how the Red Machine plays, even if it meant he had to skid painfully across the brutal plastic grass.

The Reds raced en masse to the outfield to escort Geronimo back to the clubhouse, while the Astros, huddled in their dugout, trudged into their locker room to reflect on two nights of egregious base running and almost as sloppy fielding.

The Astros, who have climbed back into first place seven times in the last 14 days after the Reds had nudged them into second, bravely admitted that they felt the twinges of pressure.

"I guess these are the first games I ever played in that meant anything," said Terry Puhl. "I felt drained after the first game (a 9-8 marathon). These guys (the Reds) can rip the cover off the ball and that's exactly what they did."

The Astros arrived here with the best team earned-run average in baseball, 3.14. They put their creme de la creme on the mound -- and they all get shallacked. Richard, after posting a 1.02 ERA in his previous 10 starts, was knocked out in five innings. Knuckle-baller Niekro (now 18-10) was finished by six runs in less than four innings tonight and had the embarrassment of seeing four of his pitches skip past rookie catcher Luis Pujols to the screen. Relief ace Joe Sambito was greeted by game-losing back-to-back homers Tuesday. Stalwart Joaquin Andujar was ripped out of the game both nights.

"This is the first time in a long time that I've felt butterflies," said Astro third baseman Enos Cabell, who is considered the team's leader.

"We think we've showed that we can play with the big boys," said Sambito. "But, also, we know that this is a learning experience for a real young team. The Reds have guys who are going to the Hall of Fame -- about six of 'em. Most of us have never even been in a pennant race before."

The Astros showed that tension and insecurity on the base paths and on defense. Five Astros, two tonight, ran through the "stop" signs of the third base coach, Bob Lillis. Miraculously, four of them scored. Otherwise, the scores here might have been more lopsided.

Perhaps the most depressing sight for the Expos was the contrast between their Punch 'n Judy attack and the rocket balls hit by the Rebs.

In two nights, the Astros, whose 46 team homers are only one more than Chicago's Dave Kingman has, had the whopping total of 28 hits. Yet they were constantly behind. While Houston's hits were chops, bloops and bleeders, George Foster and Co. were mashing balls over fences and off them.

"We just can't seem to drive in enough runs with our hits because the other team's outfielders can play us so close," said Coach Deacon Jones. "Our outfielders always seem to be back by the warning track."

When Houston got three straight hits tonight, they merely left the bases loaded. When the Reds started their first inning with three straight hits, two of them slammed off walls, the result was two quick runs and a man on third, who quickly scored, too.

"We're just a bunch of good ballplayers, not great ones, who complement each other, rather than trying to overshadow each other," said Sambito.

"No matter what happens now, no one can say we folded. We've stayed in the race too long and made too many comebacks to get stuck with that tag."

Nevertheless, the handwriting certainly seems clear. Cincinnati needs to look only at its stat sheet to see its power: the Reds have outscored opponents, 690-596. Houston, by dramatic contrast, has somehow managed to stay 17 games over .500 while actually being outscored for the season, 524-523.