Isurus and BOOM Esports pulled out 2-1 wins on Wednesday as play began in the ESL One: Road to Rio - South America event.
Isurus came from behind to beat Imperial e-Sports. BOOM needed an overtime win on the final map to get past RED Canids.
The South American competition features just four teams vying for Pro Tour points and a $10,000 prize pool. After three days of round-robin play, the first-place team will advance straight to the Sunday final. The second- and third-place teams will square off for the other berth in the final.
All matches are best-of-three.
The $2 million ESL One: Rio Major was originally scheduled to be held May 11-24 in Rio de Janeiro, but it was pushed back to Nov. 9-22 due to the coronavirus pandemic.
The regional qualifying events for Europe, South America and North America all started Wednesday. Play in the Commonwealth of Independent States region will begin April 30, with the Asia and Oceania regions kicking off May 6.
The teams are competing for a total of $255,000 in the online tournaments, as well as for ranking points to be applied toward berths at the ESL One: Rio Major.
On Wednesday, BOOM opened with a 16-9 victory on Nuke before RED Canids captured Overpass 16-7. Going to overtime on the final map, Mirage, BOOM emerged with a 19-16 win.
Imperial prevailed 16-14 on Train before Isurus took Nuke 16-13 and Inferno 16-9.
On Thursday, RED Canids will oppose Isurus, and BOOM will take on Imperial. The round robin concludes Friday with Isurus meeting BOOM while RED Canids tackle Imperial.
ESL One: Road to Rio - South America standings, with win-loss record and map differential
T1. Isurus, 1-0, +8
T1. BOOM Esports, 1-0, +1
T3. RED Canids, 0-1, -1
T3. Imperial e-Sports, 0-1, -8
—Field Level Media