Poland pulled a goal back before half-time but, left with 10 men for the final quarter of the game, they were no match for the hosts in their last game of Group Six, before a crowd of 23,110.
With his England side already assured a play-off berth for next month, Peter Taylor kept faith in Cole as a lone striker, with Aaron Lennon and Thomas supporting the Chelsea marksman from the flanks.
The captain Nigel Reo-Coker was brought back into the side after recovering from an ankle injury, while the Wigan midfielder Ryan Taylor was given his first start at Under-21 level.
With nothing riding on the game - England could not finish top and Poland, who had lost their previous meeting against England, could not get in the play-offs - the game started slowly.
Cole had the first effort on goal when he was sent through by an inventive lofted pass from Gary O'Neil. But Cole blazed well over with his volley. The striker had another effort fly wide a minute later when Lennon poked a ball through.
Cole made no mistake after 18 minutes when he raced on to a pass from O'Neil and stabbed past the goalkeeper. Thomas doubled the lead three minutes later when he sidefooted home after a cross from the right by Ryan Taylor.
Steven Taylor scored in the 37th minute when he finished off a move he started in his own half. After passing to Reo-Coker on the right flank he raced into the box to score. Marcin Kikut pulled one back a minute later for a 3-1 half-time score.
The Poland coach Wladyslaw Zmuda responded at the interval by replacing Marcin Klatt with Slawomir Peszko, but it did little to halt the hosts.Pawel Strak was the first player to be cautioned, the midfielder grabbing Thomas around the neck. A second bookable offence gave Strak an early exit in the 77th minute and Poland's fate was sealed.
England Under-21: Carson, R Taylor, Whittingham, S Taylor, Ferdinand, Huddlestone, Reo-Coker, O'Neil, Cole, Lennon, Thomas. Substitutes: Camp, Onuoha, Davies, Welsh, Milner, Moore, Stead.
Poland Under-21: Fabianski, Lukasiewicz, Telichowski, Kikut, Klatt, Gregorek, Szalachowski, Fonfara, Dudka, Burkhardt, Strak. Substitutes: Cierzniak, Wojtkowiak, Kucharski, Tralka, Peszko, Rzezniczak, Pzizga.
Referee: Mikko Vuorela (Finland)Reuse content