Atletico Madrid must not let down their guard after Wednesday's thumping Champions League win at home to Malmo, coach Diego Simeone said.
However, Group A is a tight one with Italian title holders Juventus on three points along with Malmo and Simeone said progress to the last 16 is by no means guaranteed.
"It's complicated," Simeone said at a news conference after Atletico midfielder Koke had shone for the Spanish champions with a goal and three assists.
"We have to treat each match as if it's our last, nothing has been decided yet," added the Argentine.
"The teams with fewer points, like Juventus, have home games coming up which will lift them. We have to maintain our intensity and be very careful."
Atletico's latest European success was their 19th win in their last 21 home matches in UEFA competition, their only defeat a 2-0 reverse to Rubin Kazan in the Europa League round of 32 in February 2013.
Last season, they won five and drew one of six home games on the way to the final of Europe's elite club competition, where they were beaten 4-1 by Real Madrid after extra time.
Malmo coach Age Hareide conceded that Atletico had been much the superior side and said it would be tough now for his team to secure third place in the group and qualify for the Europa League, Europe's second-tier club competition.
"We had the same intentions in the second half as the first but maybe we were lacking in energy," Hareide, whose side secured a second consecutive Swedish title this month, said.
"Now we will analyse the game and see if we can play better at home," added the former Norway defender, who had playing stints at English clubs Manchester City and Norwich City. "If we don't win the next match it's going to be very tough."
Malmo host Atletico on November 4, when Juventus are at home to Olympiakos.
Image: Antoine Griezmann (left) of Atletico de Madrid embraces head coach Diego Pablo Simeone (right) as he celebrates scoring their third goal against Malmo FF during their UEFA Champions League Group A match at Vicente Calderon stadium in Madrid on Wednesday
Photograph: Gonzalo Arroyo Moreno/Getty Images
Champions League: Ronaldo leads rout as Real outclass Liverpool
CL Roundup: Holders Real scrape past Ludogorets; Basel stun Liverpool
Costa ruled out of Maribor clash as injuries hit Chelsea
Euro 2016 qualifiers: Chiellini stars in Italy win; Dutch beat Kazakhs
Indian Super League just a week old and kicking!