The company agreed to suspend dividend payments when it raised almost $350m in 2020 to shore up its balance sheet. On Thursday it said it had hit its target of stripping $48m in costs from the business.
The results came as the company faced analyst concerns about fuel margins, with the Government passing legislation in 2020 aimed at boosting competition for wholesale supplies.
Retail margins for fuel dropped to the lowest level in more than five years in April, according to figures on the Ministry of Business, Innovation and Employment website.
Z Energy said that in the first half of the year margins had been flat on the previous years, but in the past six months were 4.9 cents per litre down on a year ago, with all of this coming from the final three months of the year.
However the company predicted the fall was temporary, with the fall driven by the recent rise in crude oil prices.
"Z does not consider this margin reduction to be structural, as it is consistent with other periods of margin compression from material input cost increases," the company said, adding that margins in April had recovered as crude prices had plateaued.
Z Energy was also positive about the impact of the Fuel Industry Act, the Government's response to its investigation into the retail fuel market which included the introduction of terminal gate pricing.
Z Energy chief executive Mike Bennetts said the changes, along with other contract changes, would open the wholesale market to greater competition.
"The uncertainty resulting from recent government interest in the fuel industry has now concluded," Bennetts said.
"Z is well positioned to respond positively to industry changes from the regulations that support the new legislation."
Shares in the company jumped close to 5 per cent and were up 9c or 3.4 per cent at $2.75 at 1pm.
On April 28, shares in the company closed at $2.54, the lowest since the company floated in 2013.
In December, Z Energy revealed it was in a major contractual dispute with the New Zealand Refinery Company over fixed fees, as the Marsden Point refinery attempted to undertake a plan to cease refining and become an import terminal for refined product.
On Thursday Z said negotiations were ongoing and expected to be concluded in May, as it repeated its view that the refinery should transition to an import terminal.