Richard Money began his spell as Cambridge head coach with an emphatic win over Mansfield.
Money, who was named U's boss earlier this week, saw his side go ahead when Michael Gash capitalised on some poor defending to score from close range.
Luke Berry diverted in Tom Elliott's effort to double their lead, before Elliot struck to make it 3-0.
Rossi Jarvis added their fourth before Jake Speight deflected in Anthony Howells' shot for a Stags consolation.
Jarvis's goal was his first for Cambridge and helped to complete a fine opening result for Money's tenure at the Abbey Stadium.
VIEWS FROM THE DRESSING ROOM
Cambridge United manager Richard Money told BBC Radio Cambridgeshire:
"There is a good group of players here, we just need to find a level of performance that can get the results consistently.
"You lead from the front whatever you do in this league and I thought ours were dominant today.
"Fourteen players have done terrific today. It's up to me to find out what those 14 and a few more can do."
Mansfield Town manager Paul Cox told BBC Radio Nottingham:
"I expect defending to be better. Defenders need to defend and, if you look at the second goal, we've tried to play football out of our area.
"I want the lads to be mentally strong and to just do the job they're paid to do."
On the injury to defender John Thompson: "It doesn't look good at the minute. It's a suspected broken leg."