Gerber relieved the injured Emery and stopped 31 shots in the Senators' 6-0 rout of the Carolina Hurricanes on Wednesday night.
"I don't think there were a lot of golden scoring opportunities by any means, but he obviously came in and knew it was a possibility that he might come in cold in a situation against a team where you know they put a lot of pressure on us," Senators coach John Paddock said. "They play a high-tempo game that you have to be really ready. It didn't happen too often, but I'm sure he was ready for that to happen."
"Top to bottom -- [Gerber] was solid all night, didn't give up anything," Heatley said. "Our [penalty kill] was there when it needed to be, and obviously our offense was there."
The Eastern Conference-leading Senators had a 2-0 edge before the game was 5½ minutes old, scored three first-period goals and added three more in the third for their third straight victory.
"We could have scored two or three more goals in the second period," Paddock said.
Emery stopped the only shot he faced before leaving due to soreness in his right hip, and was replaced early in the first by Gerber.
The former Hurricanes goalie stopped his former team and helped the Senators avenge a 5-3 loss to Carolina in October that was the only blemish on their 13-1 start.
"We came out really hard, and it was a different game than the last one," Gerber said. "The last one, they had a step on us. And today, we had a step on them."
Paddock said he expected Emery to be available to be Gerber's backup Thursday night in Pittsburgh.
Cam Ward, who supplanted Gerber as the starter two seasons ago during Carolina's Stanley Cup run, allowed goals on two of the first four shots he faced and finished with 20 saves for the Southeast Division-leading Hurricanes.
Carolina outshot the Senators 32-26, yet couldn't get the NHL's fifth-best power-play unit going. The Hurricanes generated just four chances and came up empty on them to fall to 5-9 in the last 14 games. They were shut out for the third time this season.
"We got outworked. We got embarrassed in our own building," defenseman Glen Wesley said. "It's unacceptable. The bottom line is that there is nothing to talk about. It's embarrassing. It's disappointing."
The Hurricanes couldn't beat the Senators, so they beat one of them up. Right wing Scott Walker was called for a match penalty for head-butting and throwing a late punch during a second-period fight with Fisher.
"I actually thought [Walker] was playing the body out there, one of the few guys that went out and tried to lay some hits in the first period," coach Peter Laviolette said.
Heatley put the Senators ahead 1-0 at 1:46 with his 15th goal and 12th of his career against the Hurricanes.
It didn't take long for Fisher to make it a two-goal game. He streaked down the left boards, eluded Bret Hedican and slipped the puck past Ward for his third goal in three games and 100th of his career at 5:24, prompting Laviolette to burn his timeout and chew out his team.
"We had breakdowns on each one," Laviolette said. "The second one, Cam probably would like to have back. ... You leave their top players alone in the slot, a guy like Heatley, it's in the net."
Spezza scored on a wrister from the slot to push the lead to 3-0 in the final minute of the period.
Ottawa improved to 17-1-1 when scoring first. ... Senators RW Daniel Alfredsson extended his point streak to six with an assist on Fisher's goal. He has a point in 14 of 17 games against Carolina. ... Carolina honored Cincinnati Reds outfielder and Raleigh native Josh Hamilton during a first-period break.