Last updated on .From the section Football

Scott McDonald and Lee Erwin score first-half goals

Josh Magennis pulls one back for Kilmarnock

Lionel Ainsworth adds late third for hosts

Result relegates St Mirren

Motherwell enhanced their hopes of avoiding the play-offs and also confirmed St Mirren's relegation to the Scottish Championship.

Lee Erwin played a key role in the first half, the 21-year-old striker scoring after being involved in Scott McDonald's opener.

Kilmarnock's Josh Magennis got a goal back, but Lionel Ainsworth's late strike secured the points.

It moves Motherwell to within three points of Kilmarnock and Ross County.

Anything less than three points was unthinkable for Ian Baraclough's Motherwell men after they could only draw with County last week, but it was Kilmarnock who looked the more threatening in the early stages with Paul Cairney and Magennis both forcing saves from goalkeeper George Long.

Going forward, though, Motherwell have begun to look more like the top-six team fans had been accustomed to seeing over the past few seasons, and they opened the scoring with some delightful football.

Erwin beat two players, moved the ball onto his left foot, and shot through the legs of Manuel Pascali. Craig Samson did well to make the save, but McDonald followed up to knock the loose ball into the net.

The visitors tried to respond and after Magennis' deflected shot led to a series of corners, Lee Ashcroft headed wide from inside the six-yard box.

Erwin was involved again for the second goal, and this time he added the finish too, reaching Steven Hammell's long ball before cutting inside Ashcroft and firing beyond Samson.

The home side grew in confidence and Marvin Johnson had a low drive saved before McDonald threatened again with a back-post header.

Kilmarnock needed something different, and Gary Locke made two changes at the break; bringing on Tope Obadeyi and Greg Kiltie for Rory McKenzie and Sammy Clingan, and within minutes they had got a goal back.

Josh Magennis pulled one back for Kilmarnock

Magennis profited from close range as Motherwell struggled to clear, the Northern Irishman tapping the ball over the line.

The nature of the game did not change Conor Grant stung the fingertips of Samson when given space on the right.

There was plenty of endeavour from both sides but neither goalkeeper was being too troubled, with the final ball not up to par.

McDonald fizzed a free-kick wide of the left-hand post as time ticked away, but when the Australian was unselfish when given a sight of goal minutes later it was 3-1. Ainsworth collected the ball on the right hand side of the box and fired inside the near post.

Jamie Hamill and McDonald both had efforts blocked at either end in time added on but neither could add to the scoring, and now ex-Hearts manager Locke could face the nightmare prospect of suffering relegation two years in a row.