CHICAGO -- Fergie Jenkins let out a laugh at the memory of how Cubs manager Leo Durocher would name the pitcher selected to be the team's Opening Day starter. At some point during Spring Training, usually with a couple weeks to go, Durocher would let Jenkins know with only a few words.

"He'd go, 'Hey, you've got Opening Day,'" Jenkins said. "Just like that. That's all he'd say."

Not much else had to be said. Jenkins was carving a Hall of Fame career with the Cubs in the 1960s and '70s, and he took the mound on Opening Day a record seven times for the franchise. One of those occasions fell on April 6, 1971, when Jenkins and Cardinals legend Bob Gibson locked horns in one of the great Opening Day duels in history.

Neither Gibson nor Jenkins flinched for the first nine innings, and neither left the mound as the game went into extras. It took a walk-off homer by Billy Williams in the 10th to end the battle of aces, giving the Cubs a 2-1 victory in front of a cold Wrigley Field crowd.

Over his career, Jenkins made 11 Opening Day starts, going up against the likes of Steve Carlton, Jim Palmer, Bert Blyleven and Dennis Eckersley. Jenkins remembers when his name was not the one mentioned first in the matchup, too, which was the case when the 1971 opener opposite Gibson arrived.

"The day before, it was always, 'Bob Gibson against the Cubs and Jenkins,'" he said. "It was never, 'Jenkins against the Cardinals.' He was the veteran. He had the notoriety, and he earned it. That was part of what baseball is all about. You earn the honors."

Gibson was 35 years old in 1971, but he had captured the National League Cy Young Award in two of the previous three seasons. The Hall of Fame right-hander also won the NL MVP Award in '68 -- the Year of the Pitcher -- when he fashioned a sterling 1.12 ERA.

Jenkins was no slouch, though. Going into 1971, the right-hander had a streak of four straight years with 20-plus wins, finishing in the top three in NL Cy Young Award voting twice in that span. Jenkins continued to cement his legacy in the '71 season, winning 24 games and posting a 2.77 ERA in 325 innings. That gave him a season average of 309 innings and 40 starts dating back to '67.

For context, Justin Verlander led the Majors with 223 innings in 2019. There were 49 pitchers with at least that many innings in '17. There were 45 complete games in the Majors in '19. Back in '71, when Jenkins finally won the NL Cy Young Award, he had 30 complete games on his own.

"It's all changed," Jenkins said. "We only had nine pitchers on the team. Now, you have 12 or 13. You were called upon to be a workhorse. Kenny Holtzman, Billy Hands, myself, we've got to get 250-300 innings in 35-40 starts. I had 42 starts one year. I mean, it was just part of the game."

But throwing 10 innings on Opening Day?

Jenkins lets out a chuckle.

"Look, in Spring Training, it was totally different the way you train yourselves now," Jenkins said. "We ran all the time and we pitched two, three, four, five, and at the end of Spring Training, the last game you pitched, you tried to go nine innings. I mean, you're trying to give yourself that strength that you're capable of going into the eighth or ninth inning.

"And the honor to be chosen as the Opening Day pitcher, that's a blessing in itself."

The temperature at first pitch on Opening Day 1971 was listed as 40 degrees. The 17-mph wind surely made it feel colder, especially given how it tends to blow in off Lake Michigan in early April.

"Oh yeah," Jenkins said. "You've just got to go out there. You've got to tell yourself, 'Hey, it's my turn to pitch. Let's go. Let's get it on.' That's it."

The Cardinals went six up, six down against Jenkins, who gave up a leadoff single to Ted Simmons in a third inning that went nowhere for St. Louis. In the fourth, Ted Sizemore led off with a hit, but Jenkins answered with a strikeout of Lou Brock. Then, Joe Torre went down swinging, and the Cubs escaped when catcher Ken Rudolph caught Sizemore stealing with a throw to second baseman Glenn Beckert.

In the home half of the fourth, Chicago finally broke through, taking a 1-0 lead on a Johnny Callison single that scored Ron Santo. That lead held until the seventh, when Jenkins went to work again against Torre, who was a thorn in the pitcher's side over the years.

"I faced him a lot," Jenkins said. "He was a hitter that knew pitches, knew when to swing, when not to swing. Things like that. Guys study now -- the pitchers. He did it himself. And he was a clutch hitter. He had a short stroke. He didn't have a big stroke like Mickey Mantle or Harmon Killebrew. These guys had big swings. He was short and quick."

In 1971, Torre won a batting title with an MLB-leading .363 average, led baseball with 230 hits and picked up the NL MVP Award. Torre's 32 hits off Jenkins were tied with Brock for the most off the pitcher in his career.

From there, Durocher kept making trips down the dugout to check in on his ace.

"He came by me in the eighth," Jenkins said. "And he always said, 'Hey big fella, how you doing?' I said, 'I'm fine.' He came by in the ninth: 'I'm fine.' He let me go back out in the 10th."

Brock, Torre and Jose Cardenal went down in order.

That set the stage for Williams, who faced Gibson more than any other pitcher in his career. He had more hits (45) off Gibson than anyone else. His totals for homers (10), RBIs (31) and walks (24) were bests for Williams against any one pitcher, and the most Gibson had relinquished to any one batter.

Williams singled off Gibson the first time he faced him in 1961, and he singled in his final at-bat against the pitcher in '74.

"Billy Williams hit Bob Gibson pretty good," Jenkins said. "And Bob Gibson never threw at Billy Williams. He'd throw at Ernie [Banks]. He'd throw at Santo. He never brushed Billy back. I don't know. He had a lot of respect for Billy, and Billy got his fair amount of hits off him."

In the 10th, Williams sent a Gibson offering into the packed bleacher seats in right-center field. The Cubs outfielder clapped his hands around the bases as the crowd roared, and he was met by a group of teammates at the plate. Jack Brickhouse's signature call of "Hey Hey" flashed on the television broadcast.

"Sweet Swingin' Billy," Jenkins said.

Had the Cubs not scored, would Jenkins have taken the mound in the 11th?

"Oh, of course," Jenkins said with a laugh.