THE big debate in the early stages of this SPL campaign must centre on who, if anyone, will provide a stiff challenge to Celtic.

On the evidence of Motherwell's ultimately convincing victory at Kilmarnock, Stuart McCall's side will surely again be in contention for European action at the end of the season – but their ability to mount a concerted challenge against the Parkhead side remains to be seen.

What might have been more pertinent to McCall was that the win was his first success in six games against the Ayrshire side during his 19-month tenure as Fir Park manager.

The visitors may have been helped by the fact Kilmarnock were hampered by an injury crisis among their forwards, with new Spanish acquisition Borja Perez starting on the bench.

However, after a win that moved them joint top of the table, for at least 24 hours, McCall had every right to be satisfied.

He said: "I am delighted not only with the victory but the way we went about it. It is my first victory as a manager against Kilmarnock and I am pleased to get that monkey of my back.

"We were always a threat on the break and we had the chances to kill off the game so I think we merited the win.

"It is just very pleasing for us to get our first win of the season somewhere as tough as Rugby Park. It is up to us to build on this."

Motherwell had taken the initiative from kick-off and with just 12 minutes gone, when Kilmarnock midfielder Lee Johnson was short with a pass back, Jamie Murphy intercepted before beating Michael Nelson with a nutmeg and slipped the ball past the advancing Cammy Bell to open the scoring.

With the goalscorer, full of impressive individual skill, and team-mate Keith Lasley on form, the visitors continued to catch the eye.

But they spurned chances to extend their lead and paid for it when Kilmarnock claimed an equaliser on the half-hour mark thanks to another piece of superb individual play as Gary Harkins slalomed through the Motherwell back line before hammering home a 16-yard drive.

But Motherwell were soon back in front after Michael Higdon measured a deft pass to spring the Kilmarnock offside trap and set Murphy free through the middle. His composure was exemplary as he rounded Bell and sidefooted home to to make it 2-1.

Kilmarnock came out with renewed vigour after the interval and substitute Danny Racchi drew a fine save from Darren Randolph, at full stretch, with a thumping 25-yard strike.

The home side had by then gained the upper hand but, to the frustration of their fans, lacked the guile – despite the arrival of Perez – to penetrate a well-drilled Motherwell defence.

The visitors, in fact, finished the stronger and Higdon could have put the game out of reach when he met Murphy's cross on the volley with seven minutes remaining, but could not direct his strike on target.

Afterwards, Kilmarnock manager Kenny Shiels voiced his frustration at his side's inability to extend their recent dominance of the Lanarkshire side.

He said: "I think it could have gone either way. Motherwell are a counter-attacking team who are dangerous away from home and their forwards were better than ours on the day. Yet we contributed to our own downfall.

"We do need someone who can link up play up front and Paul Heffernan is a miss. We are reconstructing how we play and it is too early to make an assessment of where we are going."