Southend's rising hopes of making an immediate return to the Championship were offered a reality check here last night as a Doncaster side which was supposed to be down in the dumps after losing the second automatic League One promotion spot on Saturday refused to roll over in the first leg of the play-off semi-final last night, despite the 87th-minute dismissal of Paul Heffernan for violent conduct.

With just one defeat in their previous 15 games, Southend had been described by none other than the Doncaster manager, Sean O'Driscoll, as the "form team" going into the play-offs, but after a frenetic 90 minutes in front of a raucous Roots Hall gathering, it was his team which appeared the more likely to earn a Wembley meeting with either Leeds United or Carlisle.

Asked, however, if he now regarded his team as favourites, O'Driscoll responded succinctly: "No". Southend's manager, Steve Tilson, who led the team to promotions in 2005 and 2006 before they dropped down a level last season, was buoyant. "We're still in it, but it's a one-off game now," he said. "Our away record has been good lately so hopefully we can turn them over up there."

The visitors will be without Heffernan for the next three matches after his loss of control near the end of a frantic game which contained some questionable challenges. The forward had been penalised for bundling over Southend's Peter Clarke, and when Charlie Mulgrew remonstrated with him, he shoved his head into Mulgrew's face. It was ill-judged but halfhearted.

O'Driscoll did not question the decision – "the referee said Paul used his head, so we have to take it on the chin" was how he put it.

As for Doncaster's player-of-the-year, Richie Wellens, he will be "touch and go" after missing this match with a hernia problem.

For all their energy and initiative in an opening half where their forward Lee Bernard threatened a breakthrough, Southend were grateful to their 'keeper Darryl Flavahan, who made an outstanding save with his feet after Jason Price had been sent through in the 64th minute by Brian Stock.

Within a minute, Southend's Adam Barrett had to make a double tackle to prevent Price from breaking through again. Southend, who had seen a firmly struck shot by Tommy Black blocked by their former Wimbledon 'keeper Neil Sullivan just before half-time, finished frantically, but Doncaster were well worth the draw.

Southend (4-4-2): Flahavan; Francis, Clarke, Barrett, Mulgrew; Black (Revell, 62), Bailey, McCormack, Gower; Walker, Barnard. Substitutes not used: Collis (gk), MacDonald, Robson-Kanu, Moussa.

Doncaster (4-4-2): Sullivan; O'Connor, Hird, Mills, Gareth Roberts; Guy (Haytor, 80) Green, Stock, Coppinger (Taylor, 90); Heffernan, Price (McCammon, 88). Substitues not used: Lee, Woods.

Referee: P Taylor (Hertfordshire).