Sauber got a jump on its midfield rivals in the constructors' championship battle when Sergio Perez bagged 18 points at Sepang, leaving Force India 21 adrift at the time.
But with the Silverstone-based team waiting on a major upgrade package for the Spanish GP, di Resta executed a marginal two-stop strategy in Bahrain to take eight points for finishing sixth. That has trimmed the gap to Sauber down to 14 points after the first four flyaway races.
Looking at the constructors' battle, di Resta said: "After what Sauber did in Malaysia, it keeps them in our sights. If we put performance on this car then we can get by them.
"Maintaining sixth this year was going to be difficult, but we'll keep on track, keep on picking up the points. And being realistic about it, if we can get results like that, then they are like wins to us as a midfield team."
Di Resta also praised his Force India team for the result it achieved in difficult circumstances in Bahrain, where travel safety concerns led to both he and Nico Hulkenberg skipping second practice on Friday.
"It was an outstanding performance by every member of the team this weekend, and under difficult circumstances," he added. "They played everything right - strategy and pit stops. I worked with my engineer to dial the car in right, and the track came to us.
"We've got to be happy and hopeful the upgrade we're going to bolt on the car keeps us in this position going into Barcelona."