Doncaster cruised to a Challenge Cup victory with a much-improved second-half display after looking as if they might make heavy weather of it against lower-rated opponents.
They started as if they intended to demolish the Stags and raced into a 22-0 lead in 16 minutes before complacency appeared to creep into their game.
It was one-sided at the start when Lee Waterman, Stewart Sanderson and Mick Butterfield ran in tries in the first 13 minutes before impressive young scrum-half Richard Wilkinson burst through to mark his full debut.
Sanderson also kicked 10 goals to take his personal points haul to 28 but when Essad Al-Zubaidi raced through for an opportunist try in the 28th minute the visitors grew in confidence.
Alex Ingerfield and James Hill capitalised on some poor defending to put Stags back in the match before Mike Emmett came on as substitute and touched down to stretch Doncaster’s lead.
Grant Edwards dived over to make it 34-18 at the interval and the second half turned into a procession as the Dons virtually scored at will. Wilkinson touched down again before Ryan Wilson marked his full debut with a try.
Doncaster suffered a double blow when Scott Spaven was stretchered off and was followed by prop Matthew Carbutt with a bad knee injury. But they stuck to their task with Chris Spurr, Sanderson, Liam Welham and Cooke adding late tries.
Doncaster: Butterfield, Morrison, Welham, Waterman, Sanderson, Cooke, Wilkinson, Carbutt, Spaven, Wilson, Leaf, Starling, Edwards. Substitutes: Robinson, Spiers, Emmett, Spurr.
Hemel Stags: Cameron, Hill, Brown, Small, Al-Zubaidi, Barbera, Young, Maloney, Simmons, Howitt, Swindells, Ingerfield, Lijzouli. Substitutes: Hudson, Bailey, M’Baraga, Aldham.
Referee: C Kendall (RFL).