Toru Oniki's side were unable to add to their first three wins in the competition, and the draw at Buriram Stadium means Kashima now sit two points adrift of table-toppers Vissel Kobe at the halfway point in the league phase.
"We made significant changes to the lineup and the younger players, in particular, played with a lot of determination from the start," said Kashima captain Kento Misao.
"We created plenty of chances, and because the young players worked so hard, we really wanted to come away with a win."
Kashima's Minato Yoshida and Haruki Hayashi were denied by Neil Etheridge in the first half, while the experienced Leo Ceara, introduced as a 56th-minute substitute, was also frustrated by the Buriram United goalkeeper.
The hosts almost stole the points when Goran Causic was found in the area by Wanderson Caju's cutback three minutes from time, but his goal-bound shot was deflected wide by the defence.
Gamba Osaka and Pohang play out thrilling draw
Gamba Osaka, meanwhile, shared a 3-3 draw with Pohang Steelers, with Kim Gwang-won scoring in the 89th minute to secure a point for the South Korean hosts.
Ryotaro Meshino's 34th-minute header had put Gamba in front but substitute Wanderson levelled 10 minutes into the second half.
Eli Adams restored Gamba's lead with a curling free kick from distance in the 69th minute, only for Jorge Teixeira to head in a second equaliser for the home side eight minutes later.
Koshiro Sumi thought he had secured the points for the Japanese outfit with his 79th-minute strike, but Kim secured Pohang's first point of the campaign under interim coach Kim Seong-jae.
The draw leaves Gamba in third place on eight points while Pohang remain in 15th, one point ahead of last-placed Newcastle Jets.
The first eight finishers in the 16-team standings progress to the next phase, while the quarter-finals, semi-finals and final will be played in a centralised finals tournament in Saudi Arabia in April and May.
