Among all the contender Barcelona seem to have Upper Hand of win the title despite the season not ended but staying at the top is also a guarantee because if they can maintain their best form even with the little points gap they can still be the champion. They are still talking the league even though they couldn't have any match in last weekend they have equal point with Real Madrid, by the time they play their outstanding match there will be ahead with three points. The outstanding match means a lot to them apart from getting their three points there will be very happy if they humiliate Osasuna just as they did to them in the first leg.
If Barcelona can win their match, they will have 3 points and 4 points more than Real Madrid and Atletico Madrid after 27 matches. After that, La Liga will have 11 more matches for each competitor and 3 or 4 points are not too big guarantee for Barcelona to win La Liga title. It's important that they have yet won their match and they can lose it too, so perhaps Barcelona will have same points like Real Madrid and only 1 point more than Atletico Madrid. We will only know it after Barcelona complete their match.
On the other hand Atlético Madrid really have a huge opportunity to top the table but they failed to do so which was also an advantage for Real Madrid to secured the second place if not there will still be in third place.
Atletico Madrid had a disappointed result last weekend but they're still in the title competition with Real Madrid and Barcelona. In coming hours, they will have a second leg tough match with Real Madrid and they must win it too. After Real Madrid and Atletico Madrid finish the second leg Madrid derby, and Barcelona have 27 matches totally in La Liga, we will have a clearer overview on the title race among three top clubs.