滞りのない、優雅な仕草でグラスに水を注ぎ込んだ。

She smoothly and elegantly poured the water into the glass.

準備運動からバタ足の練習まで滞りなく進み、レッスンは至って順調。

Proceeding from warm-up exercises to leg kick practice without a hitch, the lesson went completely smoothly.