Paul Dickov’s gutsy Rovers secured a notable scalp as they dumped the Championship’s second-placed club Watford out of the Capital One Cup.
Liam Wakefield, 19, was the visitors’ hero as he notched a cool finish to book his team’s place in the third round.
A fourth away victory on the spin was deserved against a side who could well be pushing for Premier promotion again.
While Watford made wholesale changes, Rovers boss Dickov made just two following Saturday’s victory at Colchester. Across the back four, Wakefield replaced Jamie McCombe, while up front, Nathan Tyson was handed the task of leading the line as Theo Robinson was demoted to the bench.
There was a shock name among the Rovers substitutes, with Richie Wellens, despite being told he wouldn’t be selected before transfer deadline day, earning a place. He replaced Marc de Val with 11 minutes to go.
It was Tyson who opened the scoring after only 14 minutes. Kyle Bennett surged into the box and was tripped by Gabriel Tamas. Up stepped much-travelled front-man Tyson to silence the home faithful as he slotted home his second goal of the season.
There was a scare for Dickov’s men, though, as they were saved by the woodwork just three minutes later. Lewis McGugan managed to find space just inside the visitors’ box, before letting fly with a drive which thumped the bar.
Former Nottingham Forest man McGugan was a real livewire and he fizzed a shot narrowly wide minutes later.
Watford’s increasing pressure paid off right on the half-hour mark. Odion Ighalo played in Lloyd Dyer, and he drove a sweet shot past Jed Steer to register his third goal of the season.
Just seven minutes after the restart, Rovers surged back into the lead through that unlikeliest of sources, Wakefield. The youngster raced into the box and after Dean Furman’s low cross missed Tyson, Wakefield was perfectly placed to smash home just his second senior goal at the far post.
Watford almost responded with a comical second equaliser. A mix-up at the back between ‘keeper Steer and Reece Wabara almost let McGugan in, but he couldn’t get a shot on target.
Back came Rovers and James Coppinger lashed in an effort which flicked off the ankle of a defender.
Minutes later Bennett was afforded time and space in the Watford box, only to be thwarted by a smart stop from ‘keeper Jonathan Bond.
The hosts were becoming more and more desperate, and Matej Vydra drilled a right-footed shot woefully wide, but as the game entered the final 10 minutes Doncaster professionally closed the game out.
Watford (3-5-2): Bond 6; Doyley 5 (Pudil 69, 6), Tamas 5, Hoban 7; Anya 6, McGugan 7 (Munari 69, 5), Andrews 6, Murray 5 (Fabbrini 75, 6), Dyer 8; Ighalo 7, Vydra 7.
Subs not used: Gilmartin, Angella, Doherty, Byers.
Yellow cards: Andrews (35).
Doncaster (4-2-3-1): Steer 7; Wabara 5, McCullough 6, Wakefield 7, Evina 7; Keegan 6, De Val 8 (Wellens 79, 6); Coppinger 7, Furman 6, Bennett 7; Tyson 7.
Subs not used: Marosi, Robinson, Peterson, Askins, Lund, Whitehouse.
Yellow cards: De Val (77).
Star man: Liam Wakefield.