at someone's heels

'Narnia' nipping at 'King's' heels o'seas
PRODUCT FOR TREATING HEEL FISSURES
ABC Nips at NBC's Heels
Nippon at China's heels
In U.S., Mango nips at rival H&M's heels
Letterman nipping at Leno's heels
THE TIGER AT RED CHINA'S HEELS
Pitbull snaps at Beyonce's heels
Reality bites at Take That's heels
Acer overcomes Lenovo as no. 3 PC OEM, nips at Dell's heels for no. 2 spot