In his black game against Doctor Euwe, Botvinnik made a serious mistake during the opening phase, after which he lost the game miserably:

Immediately after his masterpiece against Capablanca Mikhail Botvinnik suffered a severe setback against Max Euwe
Reuben Fine's performance in the second half of the tournament has been considerably worse than his performance in the first half. After his defeat against Max Euwe, the American preferred to stabilize his play against Salo Flohr with a quick draw:

Reuben Fine could still win the tournament despite his current run of bad form
Paul Keres defended his lead in the standings with a draw against world champion Alekhine, but this game could have ended differently — first Alekhine, and later Keres, could have obtained the win. So the draw was unsatisfactory, albeit not unfair:

Paul Keres is leading the event with two rounds to go
Capablanca and Reshevsky also drew, but this game was no longer relevant to the fight for tournament victory: