Surtain was going up against Oronde Gadsden in a one-on-one passing drill when Gadsden ran a quick slant. But Surtain beat Gadsden to the inside, tipped the pass and caught the deflection.
Later in that same drill, Jeff Ogden tried to run an out pattern on Madison. But Madison cut inside of Ogden and made the interception near the sideline.
The Dolphins later had an 11-on-11 drill, and Surtain once again came up with an interception.
"Both Sam and Pat had a good practice," Coach Dave Wannstedt said. "They played like I expect them to play."
Madison has become a regular in the Pro Bowl, and Surtain has played at that level as well each of the last two seasons.
The only question the Dolphins have at cornerback is whether Jamar Fletcher can step up in his second season and also finding a fourth corner.
Fletcher had his moments in coverage on Tuesday morning, and he is looking much better than he did last summer.
As for the fourth cornerback spot, candidates to fill the role include Ray Green, Zebbie Lethridge and rookie Omare Lowe.