move/step up a gear

to start to work or play more effectively or quickly than before.

With just five lengths to go, the German swimmer stepped up a gear and edged ahead to win the race.

• be in seventh heaven
• be in shoes
• be in someone's bad books
• be in someone's clutches
• be in someone's good books
• be in someone's hands
• be in someone's line
• be in someone's pocket
• be in someone's shoes
• be in the air
• be in the balance
• be in the ballpark
• be in the blood
• be in the can
• be in the catbird seat
• be in the chips
• be in the clear
• be in the club
• be in the dark
• be in the doghouse
• be in the doldrums
• be in the driving seat
• be in the eye of the storm
• be in the firing line
• be in the first flush of