The organisers were forced to declare early winners based on scores before gamers were disconnected and eventually suspending matches. It's believed IPs were cultivated via Skype.
Once the IPs of the tournament gamers were known the individual(s) responsible then launched a series of DDOS attacks through cheap and easily acquirable botnets.
DotaLounge and Pinnaclesports have declared that if any of the attacks are found to be 'rigging matches' then they'll forfeit bets. The claim on 4Chan remains unconfirmed but something like this was inevitably going to happen. The attacks began during the match between Evil Geniuses and Absolute Legends, reports.
EG's gamers were disconnected and couldn't re-join, leaving league admins scratching their heads. The game was postponed after a long pause with Absolute Legends awarded a default win given the score at the time of the attack.
The second attack happened during the match between Mousesports and Virtus.Pro where two VP players were forced offline, but two other players stood in for them. Another attack occurred today during a match between Kaipi and Team Empire when one of Kaipi's were disconnected but the team manage to win despite a 4 vs 5 handicap.
Team Dignitas and QPAD Red Pandas were victims next where the game was called short.
The G-1 league involves some serious amount of prize money being dolled out to winners.