Connacht coach Pat Lam has called on his team to maintain standards of performances in the GUINNESS PRO12 as they look to hang on to top spot when Ospreys visit this weekend. Lam’s Connacht have won their last four first team fixtures with their 51-34 victory at Zebre on Saturday returning them to the top of the table for the first time since November. Connacht's only defeat in their last ten contests at The Sportsground in all competitions came when Ulster were the visitors in the PRO12 on Boxing Day. Lam has made four personnel changes to the team that lined up in the bonus point win over Zebre six days ago. Caolin Blade and Rodney Ah You are both named to start while Ireland squad members Kieran Marmion and Finlay Bealham were released to join up with Connacht on Thursday and so take a place on the bench. George Naoupu is another change to the pack, starting with Aly Muldowney in the second row, while Academy player Sean O'Brien comes in to start at openside flanker, shifting his fellow Galway-born team mate and captain John Muldoon to No.8. And Lam is calling for more of the same against the Ospreys as he looks to maintain his side’s play-off charge. "Although we're playing at home, we are under no illusions as to the quality of the team we're playing and the challenge we face,” he said. "We respect what Ospreys have done as a team. They have won this competition on two occasions already and have consistently been in the top four over the years with quality squad depth. They're certainly in form, having lost just one game in their last nine and we know they will be hungry to continue their climb up the table. "For us, there was a big focus in training on tidying up the areas that let us down against Zebre last week and this should go a long way in ensuring an improvement in our overall performance to get the points on offer in front of our supporters at home." The Ospreys have lost only one of their last nine Guinness PRO12 encounters; 22-9 at home to Leinster in round 12. The Welsh region has also won their last three away games in the PRO12 and have never won four in a row on their travels in the history of the competition. Connacht beat Ospreys 21-16 at Liberty Stadium in round 5 and have only once before achieved a season's double over the Welshmen, in the regions inaugural season in 2004. The Welsh side have made six changes for the tie, with Josh Matavesi and Rhys Webb coming into the backline. In the pack there are starts for skipper Paul James, Dmitri Arhip, Joe Bearman and Olly Cracknell. Ospreys Head Coach, Steve Tandy, said: "Last week's win over Edinburgh means that we are still well in contention for a Champions Cup spot, but we realise that it was just one battle won and there are seven more to go. "With the next three games all against teams above us in the league, we know that it's a great opportunity for us to keep climbing the table if we can hit the required performance levels consistently. "There aren't many tougher places to go in European rugby this season than Connacht, they are at the top of the PRO12 for a reason and, rightly so, their confidence will be sky high at the moment. “It's a different kind of challenge to the one we faced last week when we played an Edinburgh team whose success has been built on having one of the tightest defences in the league. Connacht play an attacking brand of rugby and that's reflected in them being the top try scorers and points scorers in the PRO12." At Sportsground, 7.35pm Live on TG4 Referee: George Clancy (IRFU, 76th competition game) Assistant Referees: Andy Brace, John Carvill (both IRFU) Citing Commissioner: Tim Lowry (IRFU) TMO: Jude Quinn (IRFU)