SAINTS and West Brom have left their Championship playoff semi-final on a knife edge after a 0-0 draw at The Hawthorns.

Alex McCarthy made several big saves to deny the hosts, willed on by more than 23,000 of the 25,300 supporters inside the ground. 

Ross Stewart nearly scored with his first shot for Southampton since signing last summer but the wicked deflection was expertly saved. 

Russell Martin's side will host the Baggies on Friday with a conclusion guaranteed - whether it is settled in open play or on a penalty shootout. 

Martin made just one change to the team that beat Leeds United 2-1 on the final day of the regular season, with Sekou Mara coming in for the injured Che Adams.

The boss spoke to broadcasters ahead of the match and hopes the Scot will be back for Friday's second leg but made no promises.

He had watched the first half of Norwich City versus Leeds United on his phone in the Hawthorns dugout - with that first leg finishing 0-0.

Saints could have been undone in the first four minutes of this one with West Brom winning three corners piling pressure on.

Saints responded with set plays of their own but otherwise were unable to get a grip on proceedings for the first 15 minutes.

Flynn Downes had a huge opportunity saved by Alex Palmer from a tight angle after a give and go with Joe Aribo, as fortunes turned. 

Adam Armstrong hit the rebound into the side netting and could have done better, but should have been found later by a Ryan Manning pass that fell short in the box. 

Mara tried to salvage a chance with an acrobatic volley that flew wide before McCarthy produced a top stop to deny Grady Diangana. 

The Congolese had leapt over the Saints defenders to send a header goalwards in the best chance of the first half.  

After the break, Darnell Furlong prodded just wide of the post as West Brom enjoyed a sustained spell of pressure on the hour mark.

Martin, who had Stewart warming up on his own during the interval, introduced the Scot, Ryan Fraser and David Brooks after 70 minutes.

Both sides had a brilliant chance in the same move as McCarthy denied Diangana in space before Stewart's deflected strike on the counterattack was stopped by the foot of Palmer.

Conor Townsend was gifted a shot yards out when McCarthy killed Taylor Harwood-Bellis with a short pass after a lengthy spell of scary play - but the effort was blocked.

Fraser escaped punishment for a risky challenge on Diangana on the very edge of the penalty box as he lost his footing, which proved clear on the replay. 

That came deep into six added minutes, with McCarthy racing out to punch clear a deep throw-in with one of the last meaningful plays.

West Brom: Palmer; Furlong, Bartley, Kipre, Townsend (Reach, 90), Mowatt, Yokuslu (Ajayi, 81), Fellows (Wallace, 82), Diangana, Johnston (M'Vila, 81), Thomas-Asante (Swift, 81).

Unused subs: Griffiths, Chalobah, Phillips, Weimann. 

Booked: Johnston. 

Saints: McCarthy; Walker-Peters, Harwood-Bellis, Bednarek, Stephens, Manning (Fraser, 71); Downes, Smallbone, Aribo; A Armstrong (Brooks, 71), Mara (Stewart, 71).

Unused subs: Lumley, Charles, Bree, Rothwell, Edozie, Kamaldeen.

Booked: Downes, Harwood-Bellis.

Referee: Sam Barrott.