Goals by Brazil defender Luisao and Paraguay striker Oscar Cardozo secured victory for Benfica who have lost three of their first four league games and face fierce local rivals Sporting on Sunday.
"Of course this win can motivate us, it is a good omen for the derby," Benfica midfielder Carlos Martins told reporters.
Luisao scored the first in the 21st minute with a thunderous first-time shot from inside the box after a pass by Carlos Martins, who had done well to salvage a loose ball on the right wing from an over-hit corner.
The Israeli team responded strongly and could have levelled three minutes later when winger Gil Vermouth forced Roberto to make a reflex save after a good run on the left flank.
Benfica coach Jorge Jesus, also in the Champions League for the first time, said he was satisfied with the clean sheet.
"I'm happy we didn't suffer any goals. It was a win against a team which doesn't have a famous name, but that is a good team that will complicate the standings in the group," he said.
TESTED AGAIN
Roberto, much criticised since his move from Atletico Madrid, was tested again as Hapoel pushed for an equaliser on 36 minutes, tipping Dani Bondarv's curling shot over and rushing out to make a a clearance at Ben Sahar's feet.
"I leave here with a feeling that the result could have been different. We created danger and we missed goal chances," Hapoel coach Eli Gutman told reporters.
His team kept Benfica at bay at the start of the second half, but they failed to threaten again and conceded the second when substitute Maxi Pereira's shot was blocked by keeper Vincent Enyeama and fell for Cardozo to tap in.
Benfica playmaker Pablo Aimar looked impressive from the start and went close to crowning his performance with a goal on 27 minutes, but Enyeama just managed to tip the Argentine's sliding touch beyond his right post.
The Israelis almost grabbed a consolation goal when substitute forward Toto Tamuz sent a long-distance drive crashing against Roberto's post five minutes before the final whistle.
Olympique Lyon beat Schalke 04 1-0 in the other Group B match.
