Former Sunderland forward Daryl Murphy tucked home a 73rd-minute penalty at Fir Park after Shaun Maloney had gone down under a challenge from Steven Saunders, which earned the Motherwell right-back a red card.
Celtic had enjoyed the better of Sunday's Scottish Premier League encounter but were struggling to make the breakthrough with Georgios Samaras and Shaun Maloney among those to pass up chances.
With Marc-Antoine Fortune leaving the club for West Brom on Friday, Morten Rasmussen on loan at German club Mainz and Gary Hooper out for another month with a calf injury, Lennon has targeted a goalscorer before the transfer window shuts.
One option is Anthony Stokes with Hibernian and Celtic continuing dialogue over a possible transfer for the Republic of Ireland international, who turned down a Parkhead move to sign for Sunderland in 2007.
Lennon said: "He's an option for us, we have a couple of other options.
"With Hooper being injured, we just need a wee box player or goalscorer. Anthony certainly fits into that category.
"Whether we can get over the line, I don't know, I'll find out more on Monday."
Lennon, who has also been linked with interest in Hapoel Tel Aviv striker Itay Shechter, handed debuts to two players in Lanarkshire as Celtic bounced back from their 4-0 Europa League defeat by Utrecht.
On-loan Newcastle goalkeeper Fraser Forster had little to do but Honduras left-back Emilio Izaguirre made an assured debut, even drawing comparisons with former Real Madrid and Brazil player Roberto Carlos from Motherwell boss Craig Brown.
"I thought Izaguirre's debut was tremendous," Lennon told BBC Scotland.
"He was fantastic, I don't think he put a foot wrong all day. He was so composed and defended really well.
"His English isn't great so communication is a bit of a problem but he can play football. I thought he added an extra dimension to the back four."
Brown is also hoping to add to his squad but is still awaiting the go-ahead from chairman John Boyle.
"We're not putting a gun at the chairman's head," the Motherwell manager said.
"He is a smashing guy, very supportive, desperate to see Motherwell do well. It's a bit unfair to say you must do this and that.
"We're asking him is there a provision to get some reinforcements. We are continuing to ask that question. He is saying he will have a look at the situation."