The 15th round of the 2018 FIA Formula One World Championship began with practice Friday at Marina Bay Street Circuit as teams prepared for the Singapore Grand Prix Sunday.

Two 90-minute sessions - FP1 and FP2 - on the 5.063-kilometer (3.146-mile), 23-turn track were run under clear conditions, with FP1 taking place in the late-afternoon sun and FP2 getting underway at night with approximately 1,700 spotlights illuminating the circuit. Haas F1 Team drivers Romain Grosjean and Kevin Magnussen navigated the green surface amid the heat and humidity that is a hallmark of Singapore.

The asphalt was especially slick through turn one and between turns five and seven, turns 15 and 17 and around the final corner after being resurfaced in preparation for this weekend's event. The track's distance also changed slightly, reduced by two meters (3.3 feet) after a realignment of turns 16-17, which features a quick right-left feature that drivers navigate at around 140 kph (87 mph).

Both Grosjean and Magnussen began FP1 on the Pirelli P Zero Purple ultrasoft tire before transitioning to the Pink hypersoft tire. Grosjean's quick time of 1:42.108 came on his 14th lap shod on the grippier hypersofts. He ran 21 laps and was the 10th-fastest driver. Magnussen's best time was a 1:42.452 on his 16th lap, also set on hypersofts. He ran 20 laps and posted the 13th-quickest time.

Both drivers reported understeer while on ultrasofts, but at varying levels. Grosjean noticed a touch of understeer while Magnussen experienced a lot, specifically while in mid-corner. Switching to hypersofts gave both pilots a better sense of stability.

Speeds picked up and lap times dropped in the more representative FP2 session. Grosjean wrapped FP2 as the seventh-quickest driver with a time of 1:40.384, which was 1.724 seconds better than his best lap in FP1. His quick time came on the 10th of his 33 laps on a set of hypersoft tires. Magnussen shaved 1.298 seconds off his FP1 time with a lap of 1:41.154 to finish the session 15th overall. His fast lap came on his 10th tour as well, also while utilizing the hypersoft tire. He completed 32 laps.

Grosjean began FP2 on Yellow soft tires and Magnussen started on Purple ultrasofts. Both drivers turned seven laps apiece on these respective compounds before going back to the hypersofts.

Between the two sessions, Haas F1 Team ran a total of 106 laps - 54 by Grosjean and 52 by Magnussen.

Romain Grosjeran: "It was alright this evening. We were better than we were in the afternoon, which is always a good sign. There are a lot of things we can still improve on the car, as always on a street circuit. I think it's difficult for everyone getting the tires to work. Hypersofts to softs is quite a big difference. We just need to make sure we're good on every compound. The car felt ok, but there are a few more things we can do to get a bit faster. That said, I'm happy where we are."

Kevin Magnussen: "We didn't really have any problems, but on my side, we just didn't really hook it up to get any kind of competitive lap time. Romain showed that the car is there. I just kind of have to put my stuff together and get it out tomorrow. It gives me confidence to see that the car can do it. We'll work hard tonight and try and put it together on Saturday. It's going to be a close fight in the midfield. It'll be difficult to make Q3 in qualifying, but I'm positive that we can improve for tomorrow, at least."

Guenther Steiner: "We started off our Friday a little bit behind, but everybody did a good job. In FP2, we made a clear step forward. There's nothing major to report. We had a good session, and the speed, we're getting there ahead of qualifying tomorrow."

Check out our Friday gallery from Singapore, here.