The Genoa-based outfit stunned Roma 2-0 in the capital on Monday in their first of four straight games against some of the biggest clubs in Italy, ensuring Sampdoria remained level with fifth-placed Fiorentina on 45 points.
Fiorentina hold Serie A's final European qualifying berth on goal difference ahead of sixth-placed Sampdoria, while Inter (37) sit eighth before Sunday's fixture.
With games against Fiorentina and 10th-placed Milan to follow, Mihajlovic's men know this month could decide their season, as they aim to reel in Lazio (49), who lie third in Serie A's final UEFA Champions League spot.
"It was the first of four difficult games and we won," defender Lorenzo De Silvestri said after Sampdoria's triumph over Roma.
"Now we continue like this; in the end we will know where we stand.
"We are aware of our abilities, we are now there and we do not hide."
The 26-year-old full-back scored the opener at the Stadio Olimpico - his second goal in as many games - and labelled it "the most important goal of my career".
Sampdoria defeated Atalanta and Cagliari before their triumph in the Italian capital, while Inter have not won in four games in all competitions and will head to Genoa following their UEFA Europa League last-16 second leg against Wolfsburg.
Mihajlovic's team and the other Champions League contenders may be better off targeting Roma rather than Lazio, however, in their respective bids to qualify for next season's edition of Europe's premier club competition.
Lazio have won five straight matches in Serie A to move within a point of second-placed Roma, whose defeat to Sampdoria was their fifth without victory in Italy's top flight.
Cesena host Roma on Sunday and Lazio will welcome Hellas Verona to the Stadio Olimpico, while fourth-placed Napoli (46) take on Atalanta and Fiorentina visit Udinese.
Leaders Juventus (64) should be buoyant after their 3-0 win at Borussia Dortmund in the Champions League on Wednesday, as the three-times reigning Serie A champions surged into the quarter-finals.
Massimiliano Allegri's team will take on Genoa in round 28.
Chievo will open the round on Saturday against Palermo, before Milan entertain Cagliari, while in other fixtures, Empoli host Sassuolo and Parma meet Torino.
