Postpublished at 19:40 Greenwich Mean Time 3 December 2014
Rangers' Lewis Macleod tries his luck from the edge of the area but it's blocked by a diving Alloa body.
Early commitment on show from the Wasps.
FT: Celtic 1-0 Partick Thistle
Virgil van Dijk nets for Celtic
FT: Alloa Athletic 3-2 Rangers
Kenny Miller & Dean Shiels with second-half goals
Greig Spence (2) and Ryan McCord reply for Wasps
Roddie McVake
Rangers' Lewis Macleod tries his luck from the edge of the area but it's blocked by a diving Alloa body.
Early commitment on show from the Wasps.
Not much in the way of goalmouth action between Alloa and Rangers as of yet.
"We had a couple of late call-offs. I think we have a bug going through the squad.
"We go in with confidence and hopefully we can come here and get a result. We're definitely here to get something."
Our reporter Chris McLaughlin has been talking to the Celtic manager ahead of their meeting with Partick Thistle.
"It's going to be a tough game. They are a good team. We're going to have a lot of possession but we have to make sure we're going forward.
"We are coming more and more together and we know what's expected in every position, the confidence also helps."
And we're off at Recreation Park.
The officials have just led the teams out on to the pitch...
Kick off at Recreation Park is not too far way now...
Elsewhere today there was an SFA convention at Hampden and Barry Hearn, the sports promoter who revitalised darts, offered a few forthright views on what he thinks is wrong with Scottish football.
Hearn reckons it's a disgrace that the Premiership has no sponsor and he also believes the alcohol ban in Scottish football grounds should be lifted.
Do you agree with him? Let us know by text on 80295, tweet to #bbcscotfootball or leave a message on our Facebook page.
This is Celtic's game in hand over their Premiership rivals and a win will take them three points clear of Inverness Caley Thistle at the summit.
Alan Archibald's charges can move up to eighth with a victory.
Partick have been to Celtic Park already this season on League Cup duty and it was a big night for striker John Guidetti.
Celtic's Swedish star helped himself to a hat-trick as the home side capitalised on Stuart Bannigan's sending off to record a 6-0 win and seal their spot in the semi-final.
Celtic have bossed this fixture since that win for Thistle in 1995 and will have happy memories of last season's match at Firhill in March when a 5-1 win secured the club's third Scottish top-flight title on the spin.
So Celtic manager Ronny Deila brings in Charlie Mulgrew and Aleksandar Tonev after Sunday's 4-0 Scottish Cup win at Hearts.
Midfielder Mulgrew had recovered from a rib injury while winger Tonev, whose appeal against a seven-game ban for racially abusing Aberdeen defender Shay Logan will be heard tomorrow, makes his first start since October.
Thistle boss Alan Archibald drafts in Aaron Muirhead, Conrad Balatoni and James Craigen as Frederic Frans, Christie Elliott and Danny Seaborne drop out.
In the Premiership, Partick are looking to secure a first win over Celtic since May 1995.
On that night Peter Grant scored a rare goal for the men in green but Roddy Grant replied and Wayne Foster's double won it for the Jags.
Awaiting tonight's winners from Recreation Park are Livingston, who booked their spot in the final with a penalty shootout victory over Stranraer.
"The mood in the camp is brilliant. These guys work all day but they're all desperate to play in the semi-final. We know Rangers are a good side but we've competed well with them this season. The boys can take confidence from our two results this season.
"It's to be enjoyed, some of these boys might not play in another semi-final in their careers."
The Alloa-Rangers match kicks off at 19:30 and it's live on BBC Alba.
There should be plenty of interest in this one with Alloa unbeaten in two games against the Ibrox men this season.
The sides have met twice in the Championship and both matches have ended 1-1, but we'll have none of that tonight as the match will be played to a finish.
Celtic: Gordon, Matthews, Izaguirre, Ambrose, van Dijk, Brown, Mulgrew, Johansen, Tonev, Stokes, Guidetti. Subs: Zaluska, Bitton, Scepovic, Commons, Berget, Kayal, McGregor.
Partick: Thistle: Gallacher, O'Donnell, Muirhead, Balatoni, Carroll, Bannigan, Osman, Fraser, Stevenson, Craigen, Higginbotham. Subs: Fox, Welsh, Doolan, Lawless, McMillan, McDaid, Lindsay.
The referee at Celtic Park is Brian Colvin.
With Inverness having hammered St Mirren in the Scottish Cup on Tuesday, and tonight's games, there's plenty to talk about and we want to hear from you.
Fire a text our way to 80295, a tweet to #bbcscotfootball or get on the Facebook, external page to make your voice heard.
And here are the teams for the Challenge Cup match..
Alloa: McDowall, Doyle, Benedictus, Gordon, Meggatt, Asghar, Hetherington, McCord, Docherty, Spence, Buchanan. Subs: Gibson, Ferns, Hynd, Forsyth, Wilson.
Rangers: Simonsen, McGregor, McCulloch, Mohsni, Foster, Aird, Law, Black, Macleod, Boyd, Miller. Subs: Daly, Templeton, Clark, Faure, Hutton, Shiels, Robinson.
The referee at Recreation Park is John McKendrick.
For your enjoyment tonight we have Partick Thistle's Premiership trip to league leaders Celtic and the Challenge Cup semi-final between Alloa Athletic and Rangers at Recreation Park.