Pete Rose took one more step up the ladder to baseball immortals last night when he lined a third-inning double to center off Philadelphia's Randy Lerch to extend his six-week hitting streak to 40 games.

The Cincinnati third baseman always has enjoyed comparing his temperament and style of play with Ty Cobb, so it was appropriate that his 31st double of the season which nearly was caught by fleet Phillie Gary Maddox - tied him with Cobb for the third longest hitting streak of modern times.

Perhaps Rose's most serious challenge of his streak faced him in the nightcap of this twi-night double-header when he was scheduled to encounter the Phils' 6-foot-6 Steve Carlton, a southpaw against whom Rose is 0 for 11 this season.

Rose, who has said this twin bill looked like the single biggest hurdle in continuing his chase of Joe DiMaggio's 56-game record, tapped out weakly in the first inning.

However, the switch-hitter jumped an a 1-1 fast ball from southpaw Lerch to lead off the third and laced a liner toward left center. Maddox, shaded toward right center, made the proper play with no outs. He did not risk an almost impossible dive, choosing instead to try to backhand the ball off its first short hop.

The ball glanced off his glove and Rose barreled into second base. Two batters later, Rose dived across home plate for the Red's first run on Joe Morgan's shallow sacrifice fly to left.

Rose, who hoped to pass Cobb and tie George Sisler's 41-game streak in the nightcap, drew a walk in the fourth inning and was removed for a rest (along with Morgan) with the Phils leading, 9-1, in the fifth. The Phils went on to win, 12-2.

Rose's error on a two-out ground ball to third base in the top of the fourth with the Phils ahead, 4-1, left the gate open for the visitors to score five unearned runs in a seven-run up-rising.

When Rose was pulled from the game - not unusual strategy for Manager Sparky Anderson in lopsided doubleheader openers - his uniform was covered with dirt, his mouth grim in a frown. After winning nine of 11 games, the Reds have been outscored, 30-5, in their last 22innings.

Rose loves hitting streaks, but he vows he loves winning more.

Rose who knows how slim his chances are of catching DiMaggio, views the Cobb and Sisler records as the most significant milestones within his reach.

Sisler's 41-game mark was viewed as the significant modern record when DiMaggio was on his streak. The 41 total was the "pressure" number Joe D had to equal. All the rest was gravy. Now Rose is one away.

Rose knows he is traveling in fast company. When Cobb (1911) and Sisler (22) had their streaks, each had the same season's batting average - 420.

"It's ol' Wee Willie Keeler that I have my eye on," Rose has said. "He has the all-time National League record of 44 games, so it would be nice to eliminate any doubt."

Keeler, who set his mark in 1897, had enormous advantages. Foul balls were not counted as strikes until 1901 and traveling secretaries served as (generous) official scorers.

Hitting was so much easier in Keeler's big year, when he batted .424. that four of his teammates hit more than .355 and the entire Baltimore team batted .325.

Nevertheless, Rose, ever hungry for more goals, is glad to give Wee Willie the benefit of all doubts.

Three hours before this double-header, Rose was at batting practice - both hitting it, and pitching it to his 4-year-old son, Pete II.

The two Roses, plus a pair of Reds coaches, had the field to themselves. Rose would smash the bushel of balls, then join in the leisurely collection.

The best fun of the day for Rose was his chance to needle the Phils, his favorite time for repartee.

"Hey Fat Boy. I mean Greg," chortled Rose, "Got your contact lenses in tonight?"

Luzinski, who missed two recent games because his contacts irritated his eyes, gave a menacing look.

"Got the extra-dry ones, Greg?" needled Rose.

"I'm seeing the ball good," growled Luzinski, who homered twice and drove in five runs in the opener.

The concensus among the Phils was that they hoped the entire series would go like last night's first game.

"I hope we win and Pete gets his hit," said Phil's second baseman Ted Sizemore.

"I've seen Hank Aaron hit 755 home runs; I've seen Lou Brock steal 900 bases. And I'd like to see Pete hit in 57 games.

"Then let 'em kept sticking it down our throats that the old-time ballplayers like (Babe) Ruth, Cobb and DiMaggio were better."

Least anyone misjudge, it was Sizemore whose brilliant play almost stopped Rose's streak at 32.

"Hey, we all wanna be the guy who stops him, even though we're rooting for him," Sizemore said. "None of us minds a little attention for making a great play. That's what Pete would try to do, you can bet."

Then Larry Bowa, the Phil shortstop, saw Rose approaching.

"Hey, Hey, if I get leather on one tonight, I want an 'E6'," referring to an error on the shortstop.

"You won't get close enough to get leather on one, "Rose replied.

"I know where you're going (to hit)," Bowa said.

"You don't know where I was last night (what my recent tendencies are), Rose said. "You got no idea."

"Yeah, I'll just play you like always," Bowa said.

Rose laughed: " always...wrong."