Chelsea player-boss Gianluca Vialli snuffed out any threat of an FA Cup upset with a second half double at Boundary Park.

BBC Radio 5 Live's Alan Green reports from Boundary Park

The Premiership title hopefuls were harried all the way by Oldham before the Italian struck twice in the space of eight minutes to seal his team's place in the fourth round draw.

But the match was tarnished by a first half incident which saw referee Paul Durkin hit by a hot dog thrown from the crowd.

He was on his way to consult a linesman when the incident occurred and briefly needed treatment before the match could continue.

Chelsea ring the changes

Vialli maintained his squad rotation system by including himself, Marcel Desailly and Bjarne Goldbaek in the starting line-up and giving 18-year-old John Terry his full debut.

Marcel Desailly moves in for a tackle

Oldham's plans were disrupted by the absence of former Scotland international John McGinlay with flu and they struggled to achieve any worthwhile possession in the early stages.

Paul Reid was booked in the sixth minute for a foul on Dennis Wise, back in the Chelsea side after suspension, but Oldham had the first opportunity of the game when Lee Duxbury stabbed the ball over the crossbar following a corner.

Graeme Le Saux needed treatment after a clash of heads and it took Chelsea 24 minutes to create a clear opening but Gary Kelly saved superbly from Wise and Stuart Thom cleared the midfielder's follow-up effort.

The visitors picked up the pace with Gianfranco Zola finding the side-netting from Vialli's pass and Celestino Babayaro testing Kelly five minutes later.

But the half ended in astonishing scenes as referee Durkin was struck after Chelsea had the ball in the net through Wise.

The Oldham players insisted that Durkin had missed a handball by Babayaro in the build-up and he was hit as he went to consult the linesman. He eventually disallowed the goal before showing the yellow card to Babayaro.

Brief appearance by Flo

Chelsea took Zola off at half-time and turned to the greater aerial threat of Tore Andre Flo.

The Norwegian met Le Saux's 51st minute cross to send a header towards the top corner, but Kelly arched his back to brilliantly touch the ball away.

John Sheridan kept Chelsea on their toes with a 20-yard effort which whistled past the upright and the Londoners lost Flo with a leg injury in the 67th minute

Mark Nicholls came on and Chelsea took the lead a minute later when Vialli robbed Thom 20 yards from goal and drilled a low shot into the corner of the net.

Oldham's hopes were ended in the 75th minute when Goldbaek crossed from the right and Vialli made no mistake from six yards.

Oldham: Kelly, McNiven, Holt, Garnett, Rickers, Duxbury, Thom, Sheridan, Allott, Whitehall, Reid. Subs: Tipton, Miskelly, Innes, Swan, Salt.

Chelsea: De Goey, Babayaro, Desailly, Goldbaek, Vialli, Wise, Duberry, Le Saux, Zola, Terry, Morris. Subs: Hitchcock, Di Matteo, Myers, Flo, Nicholls.