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We present precise abundance determinations of two near-pristine dampedLy$\alpha$ systems (DLAs) to assess the nature of the [O/Fe] ratio at [Fe/H] <-3 (i.e. <1/1000 of the solar metallicity). Prior observations indicate thatthe [O/Fe] ratio is consistent with a constant value, [O/Fe] ~ +0.4, when -3 <[Fe/H] < -2, but this ratio may increase when [Fe/H] < -3. In this paper, wetest this picture by reporting new, high-precision [O/Fe] abundances in two ofthe most metal-poor DLAs currently known. We derive values of [O/Fe] = +0.50+/- 0.10 and [O/Fe] = +0.62 +/- 0.05 for these two z ~ 3 near-pristine gasclouds. These results strengthen the idea that the [O/Fe] abundances of themost metal-poor DLAs are elevated compared to DLAs with [Fe/H] > -3. We comparethe observed abundance pattern of the latter system to the nucleosyntheticyields of Population III supernovae (SNe), and find that the enrichment can bedescribed by a (19-25) M$_{\odot}$ Population III SN that underwent a(0.9-2.4)$\times 10^{51}$ erg explosion. These high-precision measurementsshowcase the behaviour of [O/Fe] in the most metal-poor environments. Futurehigh-precision measurements in new systems will contribute to a firm detectionof the relationship between [O/Fe] and [Fe/H]. These data will reveal whetherwe are witnessing a chemical signature of enrichment from Population III starsand allow us to rule out contamination from Population II stars.

Oxygen-enhanced extremely metal-poor DLAs: A signpost of the first stars?