Known for his high leg kick, variety of pitches, arm angles and deliveries, pinpoint control, and durability, Marichal won 18 games to help the Giants reach the 1962 World Series, and went on to earn 191 victories in the 1960s, the most of any major league pitcher.

He pitched a no-hitter in June 1963, and two weeks later outdueled Warren Spahn for a 1–0 victory in 16 innings; Marichal also had three one-hitters–including one in his major league debut–and six two-hitters.

Marichal was suspended and received a then-record fine, also paying a financial settlement, but the two players later reconciled, and eventually became close friends.

As a child, Marichal worked on the farm daily and was responsible for taking care of his family's horses, donkeys, and goats.

[4] His older brother Gonzalo instilled a love of baseball in young Marichal and taught him the fundamentals of pitching, fielding, and batting.

[6] Among his childhood playmates were the Alou brothers, Felipe, Jesús, and Matty, who all later played with Marichal on the San Francisco Giants.

Ramfis was the primary sponsor of the Dominican Air Force Baseball Team (Aviación Dominicana), against which Marichal pitched a 2–1 victory in his native Monte Cristi.

From the very moment the game ended, Marichal was a member of Aviación Dominicana team, enlisted to the Air Force right on the spot by Ramfis's orders.

[10] He made an immediate impression: in his debut against the Philadelphia Phillies, he struck out Rubén Amaro to begin the game and retired the first 19 batters, then took a no-hitter into the eighth inning only to surrender a two-out single to Clay Dalrymple.

He ended up with a one-hit shutout, walking one and striking out 12; his game score of 96 was the highest for any pitcher in his major league debut.

When Marichal exited to start the bottom of the eighth, the Dodgers led 4–2, but San Francisco rallied in the ninth to win the game 6–4.

From 1963 through 1969, Marichal had more than 20 victories in every season except 1967 and never posted an ERA higher than 2.76, which author James S. Hirsch calls one "of the finest pitching performances in history.

In 1968, he also earned the highest position of his career in MVP voting, finishing fifth behind Bob Gibson, Pete Rose, Willie McCovey, and Curt Flood.

This ranks among the top 20 pitchers of all time, ahead of such notables as Bob Gibson, Steve Carlton, Sandy Koufax, Don Drysdale, Walter Johnson and Roger Clemens, who each have strikeout-to-walk ratios of less than 3:1.

[13] Marichal dueled Warren Spahn, the 42-year-old Milwaukee Braves future Hall of Fame pitcher, in a night contest on July 2, 1963, at Candlestick Park in San Francisco, and the two great pitchers matched scoreless innings until Willie Mays homered off Spahn to win the game 1–0 in the 16th inning.

[27] Marichal is also remembered for a notorious incident that occurred with John Roseboro during a game between the Giants and Los Angeles Dodgers at Candlestick Park on August 22, 1965.

During the second game of the series two days earlier, Maury Wills was awarded first base after umpire Al Forman ruled that Giants catcher Tom Haller interfered with his swing; Haller claimed the Dodgers were holding their bats farther back than usual, and Matty Alou responded by doing the same, receiving a warning from Roseboro after his bat actually made contact with the Dodger catcher.

Marichal's act angered the Dodgers, and home plate umpire Shag Crawford warned both teams that any further retaliations would not be tolerated.

Instead, he was startled when, after the second pitch, Roseboro's return throw to Koufax either brushed his ear or came close enough for Marichal to feel the breeze off the ball.

Marichal raised his bat, striking Roseboro at least twice on the head, opening a two-inch gash that sent blood flowing down the catcher's face.

Roseboro, who required 14 stitches for his wound, filed a $110,000 damage suit against Marichal one week after the incident, but eventually settled out of court for $7,500.

Ironically, the Giants went on a 14-game win streak that started during Marichal's absence, and by then it was a two-team race as the Pirates, Reds and Braves fell further behind.

He took matters into his own hands as he did not want to risk Koufax being ejected and possibly being suspended for retaliating while the Dodgers were in the middle of a close pennant race.

[31] After years of bitterness, Roseboro and Marichal became close friends in the 1980s, getting together occasionally at old-timers' games, golf tournaments and charity events.

However, Marichal's 1975 didn't last long; he was lit up for nine runs, 11 hits and a 13.50 ERA in only two starts, again not making it past the fourth inning, before retiring less than two weeks into the season.

[13] Marichal pitched a no-hitter on June 15, 1963, a 1-0 shutout of the Houston Colt .45s; he retired the first 14 hitters, allowing only a pair of walks, and struck out Brock Davis to close out the win.

He threw five pitches – fastball, slider, changeup, curveball, and screwball – for strikes in three different angles: over the top, three-quarters, or sidearm, giving him a wide-ranging repertoire.

When Roseboro died in 2002, Marichal served as an honorary pallbearer at his funeral and told the gathered, "Johnny's forgiving me was one of the best things that happened in my life.

On July 20, 2003, Marichal was inducted into the Hispanic Heritage Baseball Museum Hall of Fame in a pregame on-field ceremony at Pac Bell Park.

Marichal, in spring training at the time, sought to return to his home country in order to bring Alma back with him to the United States.