That One Night: Live in Buenos Aires is a live album from Americanheavy metal band Megadeth which was released on CD and DVD formats. It features a live concert recorded in Buenos Aires on October 9, 2005 at the Obras Sanitarias Stadium. The performance is segued by cuts of Dave and Glen performing a few acoustic songs for some fans on the lawn outside of the band's hotel. It was at this concert that Dave Mustaine announced that Megadeth would continue on past the 2005 tour.
There are also four currently unreleased songs from the performance, missing from either the CD or DVD version: ("The Scorpion", "Train of Consequences", "Of Mice and Men" and "Sweating Bullets"). The 2 CD version was released on September 4, 2007. It was originally intended to be released at the same time as the DVD. The DVD was certified gold in the US for a shipping of 50,000 units. This is the only release by Megadeth to feature bassist James MacDonough.
Allmusic's Greg Prato rated the album at four stars and called That One Night "further hard proof" that Megadeth is "one of the most precise and tight thrash bands".
About.com's Chad Bowar also rated the album at four stars and stated "everything came together well for this release. The crowd is outstanding, even singing along to guitar riffs, and the band is in great form. The audio quality is excellent, and captures enough crowd noise without being distracting. Megadeth is one of the great thrash bands of all time, and this live CD is a good representation of their repertoire".
PopMatters's Andrew Blackie wrote in his page and praised That One Night as a work superbly filmed, focusing on both capturing the facial expressions of the band members in mid-solo and the flashing light show, and the reaction of the bordering on over-enthusiastic crowd, who seem to know every word of every song, juxtaposing this with occasional footage of an incognito acoustic performance for fans earlier in the day. Blackie gave the album 8/10.