The Red Giants edged Manzoor Azwira's Penang side 1-0 in a dull affair at Selayang Stadium, prompting Zainal Abidin Hassan to ask for more from his attackers.
Selangor are on 14 points from eight matches, seven points behind league leaders Felda United. The table-toppers gave PDRM a 4-0 lesson in Jengka while second-placed Johor Darul Ta'zim are second with 20 points after defeating Sarawak 5-2 in Larkin.
The win was also the first time in 12 matches, across all competitions, that Selangor have kept a clean sheet.
But it still was not enough for Zainal, who feels his team have not found their footing yet.
"Each win we get is important, but we have more work up ahead ... a lot of work actually," said Zainal.
"We plugged the holes at the back but lost some edge up front. There were chances, especially towards the end, but we didn’t take it.
"I know these players and the performance we saw today is still far away from what we are capable. These wins (including the 2-1 win over Sheikh Jamal last week) will bring confidence but we need to build on that with more wins.
"Confidence will bring a winning mentality and that usually brings the best out of players.”.
Argentine Mauro Olivi, back in the squad after a club suspension for a dressing room bust-up with Hafiz Kamal, scored the only goal of the game against Penang from a free-kick in the 17th minute.
It was Selangor's only attempt on goal in the first half as the Red Giants never really threatened to score a second until the introduction of leading local scorer R. Gopinathan in the 73rd minute.
Another second-half substitute, Adam Nor Azlin, had a glorious chance to seal the win in the 80th minute but he ballooned his shot despite facing an unguarded goal.
Osas Saha came close to making the 20-year-old pay for his miss but he ran out of space for a clean shot after rounding goalkeeper Khairul Azhan Khalid at the other end almost immediately after Adam's glaring miss.
Selangor visit PDRM on Saturday. The Cops, having knocked Zainal's men out of the FA Cup in February, will be eager to bounce back after Wednesday's loss to Felda resulted in them dropping from third to fifth in the standings.