Chelsea survived a late scare in the FA Cup to overcome Hull City 2-1 at the KCOM Stadium on Saturday.
Kamil Grosicki scored late on for Hull and although they pushed hard for the equaliser, Chelsea held on.
"It is not easy coming here. We had a lot of shots again. It is a frustrating period again for us again," Lampard said. "We have to remain very secure if we are going to only score once or twice."
Hull started the game brightly but it was Chelsea who took the lead in the opening six minutes when Batshuayi's deflected close range effort found the net.
"I am pleased with Michy and for him to score his goal. I want him firing and he has to stay at that level," Lampard added.
The visitors doubled their lead just after the hour mark when Tomori headed in from Ross Barkley's free kick.
With 13 minutes remaining, Hull got themselves back in the game when Grosicki's free kick deflected off Mateo Kovacic and found the net, but they failed to grab an equaliser.