Daegu FC scored six goals in their home match against FC Seoul, while Jeonbuk and Ulsan continued their strong form with wins against Incheon and Seongnam.
Daegu came into their match with six points from their first five games, level with FC Seoul. However, the hosts clearly showed their dominance by putting six goals past their opponents.
Notably, striker Dejan Damjanovic also scored his first goal for Daegu in this match, against his former club.
Elsewhere, both Ulsan and Jeonbuk managed 1-0 home wins on Saturday to remain almost neck-and-neck atop the K-League standings.
The Tigers needed another late winner from Junior Negrao winner to collect all three points, while a penalty from veteran striker Lee Dong-Gook helped the defending champions retain their place at the top.
The leading pair have also managed to put some distance between themselves and the rest of the pack, as third-placed Gangwon were held to a 2-2 draw against Suwon Bluewings after a late equalizer for the hosts.