The time-match in my thread of longest matches comes from official Grand Slam tournaments. Muller-Lopez played 262-minute match in Melbourne according to the Aussie Open website.
Thanks, I see that the ATP has updated with that time as well. The weird thing is that I can't see any stats on the AO website for that match, there's no 'match statistics' link to click
Also, I think you may have an error in your thread in the Hanescu-Hernych match. Both ATP and AO list it as around 250 minutes (ATP 252, AO 249), as opposed to your 272.
I am a little wary of all the AO time numbers, since there are some oddities on both sites. For example, ATP has Federer-Seppi as going 280 minutes, while the AO site doesn't have a time for set 3
There are a couple of other weird ones as well.
Good thread. Thanks for the stats.