Neil Lennon believes Leigh Griffiths has brought a refreshing change to Celtic recently.

The 30-year-old Hoops striker was out of the picture earlier in the season due to fitness issues which brought criticism from his manager in the summer.

However, Griffiths has worked his way back into contention and after coming off the bench to score in the William Hill Scottish Cup final win over Hearts at Hampden Park last weekend, which went all the way to penalties, he has started twice in a row for the first time this season.

The Scotland international followed up his goal in the 2-0 home victory over Ross County on Wednesday with another in the 3-0 St Stephen's Day win at Hamilton.

Lennon was happy with three goals in a week for Griffiths and he told Celtic's YouTube channel: "I thought he played very well.

"It was a great goal and I thought he could have had a hat-trick. He will be disappointed.

"But yes, he has been a breath of fresh air in the last few weeks.

"So it is (about) keeping him fit and keeping him at it."

French striker Odsonne Edouard netted a penalty just after the break and midfielder David Turnbull added a third goal after Griffiths had scored with a drive from inside the box to keep Celtic 16 points behind Rangers at the top of the Premiership with three games in hand.

The champions play Dundee United on Wednesday before travelling to Ibrox on 2 January.

Lennon said: "We have a bit of work to do, we know that.

"We look forward to the Dundee United game and look to win that and take things from there. But I am delighted with the form we are in.

"I thought the two centre-halves (Nir Bitton and Kristoffer Ajer) were  excellent, the two full-backs (Jeremie Frimpong and Greg Taylor) were great, the whole team functioned perfectly, the way we want them to."