This was a surprising relegation tussle, because the two teams were stuck together on 26 points, just four clear of the drop zone.
Bram Nuytinck was still out of action, but Roberto Pereyra was fit for his first start since November. Morten Thorsby sat out a ban for Samp, with Mikkel Damsgaard, Manolo Gabbiadini and Andrea Conti injured, but Bartosz Bereszynski and Antonio Candreva returned from suspension.
It took barely four minutes to break through, as Pereyra burst down the right, pulled back from the by-line and Gerard Deulofeu took a touch before scoring from six yards at the near post.
Deulofeu was the provider for the second goal, pretending to shoot just inside the box, but instead rolling it across for unmarked Destiny Udogie to sweep home.
Moments after that, Ciccio Caputo got one back for Samp, running onto a Maya Yoshida ball over the top and shrugging off Pablo Mari to fire in. It required a very long VAR check, so it was extremely tight as he sprung the offside trap.
Walace went even closer, his header from a corner thumping the crossbar with Falcone beaten on 67 minutes.
Sebastian Giovinco made his Sampdoria debut after arriving as a free agent in February, but Udinese continued to have the best chances with Deulofeu firing wide.
Udinese 2-1 Sampdoria
Deulofeu 4 (U), Udogie 12 (U), Caputo 13 (S)