Oscar had the magic touch for Chelsea as the European Champions got their Europa League campaign off to a winning note, while Liverpool crashed to Zenit with Gareth Bale again single-handedly carrying Tottenham to victory.
Chelsea looked like they were on their way to a 0-0 draw at Sparta Prague, before Oscar, with pretty much his first touch of the ball, glided through the Czech club's backline to produce a sublime finish in the 82nd minute and give his side the advantage going into the second leg of the round of 32 tie.
"Eighteen attempts away is not bad, but we have to be more clinical in attack," Benitez said. "The first 20 minutes we were in control. We had some half-chances, it was a cross, we weren't there. We were in control.
"After this 20 minutes they were pushing and pushing. The team, as a team, had problems defending.
"We changed a little bit in the second half. I think the concentration of the team was much better, the intensity in defense was much better and then we had more control."
At the Petrovski Stadium, Zenit got the better of a flat Liverpool side 2-0, thanks to second half goals from Hulk and Sergei Semak.
Luis Suarez, very much unlike him this season, missed two golden opportunities, as Liverpool struggled to come to grips with a difficult surface.
Hulk forced a couple of first half saves from Pepe Reina, and even hit the post, before netting the opener with a terrific long-range strike in the 70th minute. Two minutes later it was 2-0, as Semak pounced on a cross at the far post to guide the ball in.
Liverpool now have a mountain to climb to book themselves a place in the last 16 when the two teams meet for the second leg at Anfield next week.
"There is no way the tie is over, not by a long shot," Liverpool manager Brendan Rodgers said. "We are more than capable of getting the goals back.
"I think the next goal is vitally important for us and what gives us hope is we created enough to win the game. If we get it early it can create the momentum for us."
At White Hart Lane, it was the Bale show as the Welsh international scored at the end of either half - both via freekicks -- to give Spurs a narrow 2-1 win over Lyon, while at St James' Park Newcastle were frustrated by Metalist Kharkiv in a goalless draw.
In other games, defending champions Atletico Madrid are on the brink of an exit after going down 2-0 to Rubin Kazan at home, while Napoli were shocked by Viktoria Plzen 3-0 in Naples.
Rodrigo Palacio's twin strikes gave Inter Milan a 2-0 victory over CFR Cluj, while Ajax won by the same scoreline against Steaua Bucharest.
Results: Zenit 2-0 Liverpool; Anzji 3-1 Hannover; BATE 0-0 Fenerbahce; Levante 3-0 Olympiakos; Leverkusen 0-1 Benfica; Ajax 2-0 Steaua; Sparta Praha 0-1 Chelsea; Napoli 0-3 Plzen; Dynamo Kyiv 1-1 Bordeaux; Newcastle 0-0 Metalist; Tottenham 2-1 Lyon; Internazionale 2-0 CFR Cluj; Stuttgart 1-1 Genk; Atletico 0-2 Rubin; Basel 2-0 Dnipro; Monchengladbach 3-3 Lazio.