Best pitching performance in a MLB game

[SingingAnalyst]

Neither was a perfect game.

1. Harvey Haddix, Pittsburgh, May 26, 1959: Against the Milwaukee Braves in Milwaukee, Haddix pitched 12 perfect innings. His team, while recording 12 hits, couldn't score against Braves pitcher Lew Burdette: in the 3rd inning the Pirates failed to score despite 3 hits, due to a mistake on the basepaths; in the 7th, a hard-hit ball was caught on the warning track, having been knocked down by shifting winds; any other inning it probably would have been a homer. In the top of the 13th the Pirates were out 1-2-3; in the bottom of the 13th the perfect game fell apart (including an intentional walk to then-relatively unknown Hank Aaron) and Haddix and the Pirates lost.

2. Armando Galarraga, Detroit, June 2, 2010: the "28-out" "perfect game": https://en.wikipedia.org/wiki/Armando_Galarraga#%22The_28-out_perfect_game%22

Any others?

[SingingAnalyst]

As a consolation to Haddix, he recorded 2 wins in the 1960 World Series, in which the Pirates were ultimately victorious.

[GeorgiaModerate]

About 20 years ago I watched (on TV, not live) a Braves game where Greg Maddux pitched a complete game in 76 pitches, over 60 of them strikes.  That was the most amazing pitching performance I've ever seen.

[Amenhotep Bakari-Sellers]

There isnt much pitching going on, due to 1997 homerun furby between McGuire and Sosa. Fans come to ballgames to see homeruns, due to advent of steroids and ball being juiced.

There are no more Dennis Eckersons

[This user has not been convicted of 34 felonies]

It's not a traditional answer, nor is it statistically the most impressive, nor was it even a win, but Nathan Eovaldi coming out to pitch 6 innings in relief during Game 3 of the 2018 world series and then ASKING FOR THE BALL THE NEXT DAY was the most amazing thing I've ever witnessed and no matter how much he sucks going forward, I'll never forget that game.