Celtic winger James Forrest celebrated his new contract with a goal as the Scottish champions beat St Mirren 2-0, while title rivals Rangers routed Ross County 4-0 on Wednesday.

Forrest grabbed Celtic's second goal after the interval at Parkhead, just hours after signing a one-year contract extension which ties him to the club until 2023.

The 28-year-old came closest to breaking the first-half deadlock as St Mirren defended in numbers and displayed good skill and composure to net in the 54th minute.

Mohamed Elyounoussi had opened the scoring five minutes earlier from close range as Celtic ensured they remain top on goal difference.

Rangers ripped Ross County apart at the Global Energy Stadium, but remain just behind Celtic in second place.

Colombia striker Alfredo Morelos got the visitors up and running in the 20th minute when he knocked in a pass from Sheyi Ojo for his 17th goal of the season.

Ryan Jack scored twice to put Rangers in control by the interval.

Morelos grabbed his second with a drive in the 72nd minute, but Steven Gerrard's side couldn't add the extra goals that would have knocked Celtic off the top.

Hibernian's Martin Boyle enjoyed a fairytale return from injury in a 2-2 draw against Livingston.

The Lions raced into a two-goal lead courtesy of a double salvo on the cusp of half-time, with Steven Lawless and Craig Sibbald finding the net.

Scott Allan got one back from the penalty spot and Boyle, climbing from the bench following four months on the sidelines with a serious knee injury, restored parity in stoppage time to secure a fifth draw in a row for Hibernian.

Motherwell moved into third place with an 2-1 win against 10-man Kilmarnock, while Aberdeen were 1-0 winners at Hamilton and St Johnstone beat Hearts 1-0.