Kane scored 20 points, Niang had 19 points and eight rebounds and the 17th-ranked Cyclones kept the Horned Frogs winless in the Big 12 with a 71-60 victory Saturday.
Niang had two three-point plays in the last 5 minutes to help build a cushion, and Iowa State (21-5, 9-5 Big 12) finished the day in a three-way tie with Texas and Oklahoma for second place in conference after the Longhorns lost to Kansas and the Sooners beat Kansas State, dropping the Wildcats to fifth.
''Huge plays by Georges,'' Cyclones coach Fred Hoiberg said. ''He's been a guy we've gone to late in games, and he's done a great job for us.''
Kyan Anderson, who averaged 26 points in his past four games, scored 18 points to lead TCU (9-17, 0-14). The Horned Frogs are 2-30 in the conference in two Big 12 seasons.
''What hurt us is not knocking down shots when it counts and lots of turnovers toward the end as a team,'' Anderson said. ''It hurt us.''
Ejim, the Big 12 leader at 19.1 points per game coming in, scored 14 after setting a Big 12 record with 48 in Iowa State's 84-69 win over at TCU at home two weeks ago.
He never really had a chance to challenge his record, picking up two fouls in the first 6 minutes while TCU was building a 13-3 lead and playing just 10 minutes in the first half.
''It was a tough start,'' Ejim said. ''When you get two fouls that quick, you can't really get into a groove. Tough for me, tough for the team, we were able to fight through it.''
Ejim did have a hand in the play that gave the Cyclones their first double-digit lead, picking up the ball after Kane knocked it away from Anderson and throwing a long pass back to Kane for a layup with 2:34 remaining.
Once Iowa State erased TCU's early 10-point lead, the teams weren't separated by more than three points until Ejim converted inside to put the Cyclones ahead 54-50 with 9 minutes to go.
The Iowa State lead was two points after a driving layup by Anderson, but Kane answered inside on the other end to start a 10-1 run.
The first three-point play for Niang came when the TCU bench thought the burly forward should have been called for charging on freshman center Karviar Shepherd, who scored 14 points and had 15 rebounds, one off his career high.
Niang had another three-point play when he was fouled by the much shorter Christian Gore on a short turnaround from the baseline. The free throw put Iowa State up 67-58 with 3:11 to go.
''Once we picked it up, we were better,'' Hoiberg said. ''But still we gave them the confidence early in that game to hang around and to have a chance. I tip my hat to those guys for playing hard, but I'm glad we found a way to win it.''
TCU, already thin in the frontcourt because of injuries, was without second-leading scorer Amric Fields, who has been dealing with soreness in a surgically repaired right knee that kept him out most of last season.
''We're improving a lot from beginning of the season, from the beginning of conference,'' Shepherd said. ''We're doing what we can to improve with the players that we have out there. We're playing pretty well, but at the end, we need an extra spurt.''
Dustin Hogue had eight points and eight rebounds for the Cyclones.
Jarvis Ray scored 10 points for the Horned Frogs, who missed the front end of the bonus on free throws twice when they were down seven points late and shot 37 percent for the game.
''We were in a pretty good situation throughout the first half and late in the second half,'' TCU coach Trent Johnson said. ''The ball didn't go down for us.''