Melbourne - Ferrari blamed their lack of a competitive edge at the season-opening Australian Grand Prix on Sunday on balance issues, with Sebastian Vettel complaining the car's performance around corners was not good enough.
The powerhouse Italian team was the standout performer in pre-season testing in Barcelona, but they have been consistently off the Mercedes' pace in Melbourne.
Four-time world champion Vettel could only manage fourth at Albert Park, trailing a gaping 57.1 seconds behind winner Valtteri Bottas.
His Ferrari partner Charles Leclerc was fifth.
"In Barcelona we were very happy with the car right from day one. I think the balance was right, the car was responding to what I was asking it to do. I had a lot of confidence," said Vettel.
"I think all weekend I didn't get that confidence I had in Barcelona. It (the car) wasn't doing what I was asking.
"I think there were glimpses here and there that were really strong. The performance in some corners was really good, but in the majority it wasn't and that's why we were slower than other people and lost out today."
Team principal Mattia Binotto said it wasn't clear exactly what the problem was, but it was related to the balance setup.
"Since Friday FP1 (free practice one) we have not found the right balance, we struggled at times," he said.
"Do we understand that yet, probably not. It's something we need to go back and analyse and try to assess what happened.
"One thing we are certain of is that this weekend is not the real potential of our car. The potential is certainly bigger."
Mercedes have been dominant in Formula One in recent years, winning the drivers' and constructors' titles five years in a row, and Ferrari - and Vettel -- are desperate to catch up.
"Clearly we're missing something right now, but we don't have an answer," said the German.
"We need to get back, have a good look and I'm sure we'll find something because we know that the car is better than what we have seen today."
Results from the Australian Formula One Grand Prix after 58 laps of the Albert Park circuit in Melbourne on Sunday:
1. Valtteri Bottas (FIN/Mercedes) 308 km in 1hr 25min 27.325sec
2. Lewis Hamilton (GBR/Mercedes) at 20.886 sec
3. Max Verstappen (NED/Red Bull) at 22.520 sec
4. Sebastian Vettel (GER/Ferrari) at 57.109 sec
5. Charles Leclerc (MON/Ferrari) at 58.230 sec
6. Kevin Magnussen (DEN/Haas) at 1:27.156 sec
7. Nico Hulkenberg (GER/Renault) at 1 lap
8. Kimi Raikkonen (FIN/Alfa Romeo) at 1 lap
9. Lance Stroll (CAN/SportPesa Racing Point) at 1 lap
10. Daniil Kvyat (RUS/Toro Rosso) at 1 lap
11. Pierre Gasly (FRA/Red Bull) at 1 lap
12. Lando Norris (GBR/McLaren) at 1 lap
13. Sergio Perez (MEX/SportPesa Racing Point) at 1 lap
14. Alexander Albon (THA/Toro Rosso) at 1 lap
15. Antonio Giovinazzi (ITA/Alfa Romeo) at 1 lap
16. George Russell (GBR/Williams) at 2 laps
17. Robert Kubica (POL/Williams) at 3 laps
Fastest lap (1pt): Bottas 1:25.580
Retirements:
10th lap: Carlos Sainz Jr (ESP/McLaren) engine
30th lap: Daniel Ricciardo (AUS/Renault) mechanical problem
30th lap: Romain Grosjean (FRA/Haas) mechanical problem
Drivers championship standings:
1. Valtteri Bottas (FIN) 26 pts
2. Lewis Hamilton (GBR) 18
3. Max Verstappen (NED) 15
4. Sebastian Vettel (GER) 12
5. Charles Leclerc (MON) 10
6. Kevin Magnussen (DEN) 8
7. Nico Hulkenberg (GER) 6
8. Kimi Raikkonen (FIN) 4
9. Lance Stroll (CAN) 2
10. Daniil Kvyat (RUS) 1
Constructors:
1. Mercedes 44
2. Ferrari 22
3. Red Bull 15
4. Haas 8
5. Renault 6
6. Alfa Romeo 4
7. SportPesa Racing Point 2
8. Toro Rosso 1