Sometimes in high-level competition, you may face an opponent who can detect hip throws coming a mile away.
As a response to your Tsurikomi goshi, the opponent may bend over and take their hip away from you. No hips, no throw!
The solution in this case is to release the lapel grip and use the same hand to grip the opponent’s gi from the lower back or from the belt.
This way, you will have control over the hips of your opponent, and you will be able to keep them in place in order for you to get your hips under them.