Ferrari’s flagging Formula One season really needs a timely boost at the Monaco Grand Prix, and Fernando Alonso’s encouraging form in practice has raised hopes he can beat Sebastian Vettel tomorrow.

Alonso set the fastest lap in Thursday’s second practice, the first time Ferrari has done so in practice this season.

But the two-time former F1 champion is wary Vettel may have been holding back, preferring to test the durability of the new supersoft optional tyres, and fears Red Bull will hit top form in today’s qualifying.

“We know this is just the first day and that the Red Bulls could be hiding a bit before coming out for qualifying,” Alonso said. Vettel had been fractionally quicker on the first session, just ahead of Alonso.

Vettel failed to take pole position for the first time this season at last week’s Spanish Grand Prix, but still won the race and the defending champion already leads Lewis Hamilton by 41 points after just five races.

Alonso, last year’s F1 runner-up, is 67 points adrift and desperately needs a win to get his title challenge back on track.

The Spaniard has one podium so far, finishing third in Turkey, but Red Bull fear he will creep back in contention.

“Fernando came from a long way back last year to lead into the final race of the World Championship, so we don’t underestimate any of our rivals,” Red Bull team principal Christian Horner said. “The points are quite deceptive and the gaps look large at the moment, but there is a long, long way to go in this championship.”

Vettel has won four of the five races so far and finished second in China, but some of those wins were hard-fought.

“It has been phenomenal racing,” Horner said. “Sebastian has had to work for those victories. At every Grand Prix he has won he has had to pass somebody for the lead, and in Spain last weekend he had to work very hard.”

It will take more than one day’s good practice and some compliments from Horner, however, to convince Alonso that Ferrari’s 150 Italia is any closer to matching the Red Bulls for outright pace.

“The aerodynamics count for less in Monaco and so we are suffering less,” Alonso said. “On a track with the lowest average speed of the season, some weaknesses are hidden by other factors, such as the mechanical side and the engine.”

Knowing that speed will not be of the essence tomorrow, Vettel put in one of the longest shifts in Thursday’s second practice to gauge what he should expect from the supersofts in today’s qualifying and on race day.

“It’s been positive so far. Both tires are working well and seem to be lasting,” Vettel said. “The supersoft tire seems to be the preferred one for qualifying. It seems to be quicker and you can extract more lap time out of it.”

Drivers were expecting the supersofts to degrade quickly, perhaps leading to another pit-stop show like in Turkey, but have been clearly surprised by how resilient they are. Pirelli expects most teams to adopt a two or three-stop strategy tomorrow, rather than the four-stop chaos of Istanbul.

“It doesn’t look bad because if you look at the long run of Vettel, for example, he did 20 laps, no problems,” Hamilton said. “So you might see a different race. Maybe it won’t be as spectacular as we had hoped because the tyres are lasting.”

But it is clear Alonso needs a great performance in qualifying to pressure Vettel from the outset.

If he finds himself sitting behind Vettel on the grid, and with overtaking so hard on Monaco’s mazy, twisting 3.34-kilometre street circuit, it could turn out to be yet another demoralizing afternoon for Ferrari.

Hamilton, the only driver to beat Vettel this season in China, showed some excellent form in practice.

The English driver makes no secret of loving the Monaco track and is quietly confident of winning here for the first time since 2008, the year he became the youngest ever driver to win the championship — a record Vettel broke last year.