Barca, who won 2-0 at English Premier League side Manchester City and Atletico, who beat Italian club AC Milan 1-0 at the San Siro, are tied on 60 points with Real Madrid at the top of Spain's domestic league with 14 matches remaining.
Real have to wait until next Wednesday before they play their Champions League last 16, first leg at Bundesliga side Schalke 04 and coach Carlo Ancelotti could rest a number of key performers for Saturday's visit of promoted Elche.
Barca play at Real Sociedad, who are sixth and targeting a European qualification berth, on Saturday and Atletico travel to Pamplona to take on Osasuna on Sunday.
Barca's performance in Manchester helped refute any suggestions the Catalan giants are a declining force, while Atletico's gritty win in Milan was further evidence they are genuine challengers for domestic and European silverware.
Barca suffered a surprise La Liga reverse at home to Valencia at the start of the month and Atletico took over at the top before they stumbled at Almeria and the champions returned to the summit on goal difference.
They thrashed Rayo Vallecano 6-0 at the Nou Camp last weekend and Barca goalkeeper Victor Valdes said the win at City had left the squad in a "very positive" frame of mind.
"We won the ball back very quickly and the way the game turned out was very good for us," Valdes, who has rejected a contract extension and is set to leave at the end of the season, told reporters.
"Barca is a rival you can never discount," added the 32-year-old.
"There has been a lot of talk about whether we are pressing our opponents in the same way as before but what we all want is to go as far as we can."
One reason Barca appear to be back on track is the form of their Argentina forward Lionel Messi since he returned at the start of January after a two-month injury layoff.
The four-times World Player of the Year has netted 11 times this calendar year, including six in his last four appearances, and has 25 in all competitions.
Real also look to be in fine form as the season enters a critical phase.
Carlo Ancelotti's side have gone 25 matches without tasting defeat, equalling their second-best run from the 1996-97 campaign when Ancelotti's Italian compatriot Fabio Capello was in charge. Their record is 34 games unbeaten from 1988-89.
Saturday's match against Elche is the last one La Liga top scorer Cristiano Ronaldo will miss before completing a three- match suspension handed down after his dismissal in the 1-1 draw at Athletic Bilbao on Feb. 2.