KRASNAYA POLYANA, Russia — Dario Cologna had the strongest finish to win the men’s 30-kilometer skiathlon at the Sochi Olympics on Sunday, showing he’s back to full fitness after a season disrupted by an ankle injury.

The Swiss cross-country skier pulled away from a quartet of rivals at the top of the last uphill section and then held off defending champion Marcus Hellner of Sweden on the final straight.

Cologna finished in 1 hour, 8 minutes, 15.4 seconds for his second Olympic gold medal. Hellner was 0.4 seconds behind to win silver, with Martin Johnsrud Sundby of Norway taking bronze.

Cologna is a three-time overall World Cup winner and became the first Swiss cross-country skier to get an Olympic gold when he won the 15K freestyle race in Vancouver four years ago. However, he missed the first two months of this season after he needed surgery to repair an ankle ligament in November and only returned to competition last month.

He had shown last weekend that he was returning to form by finishing second in a World Cup race, and left no doubt on Sunday that he’s back to his best.

Cologna stayed well back in the pack for most of the 15K classical style portion of the race before moving his way up the field after the switch to freestyle at the halfway point.

About 15 skiers were still in the main pack entering the last 2 kilometers, but when Hellner made a move up the steep hill just outside the stadium, only Cologna, Sundby and Maxim Vylegzhanin could keep up. Cologna then pulled in front near the top and immediately opened up a gap of about 10 meters to Hellner. The Swede pulled closer in the final sprint but couldn’t catch his Swiss rival.

Double Olympic champion Petter Northug of Norway totally ran out of energy on that final hill, dropping way back and out of contention. Northug is a two-time world champion in the skiathlon but has struggled with an illness this season and Sunday’s performance suggests that he still hasn’t fully recovered — a worrying sign for Norway’s biggest star on the men’s side. A lethargic-looking Northug skied down the final straight at a slow, walking pace and he ended up 17th, 1:24 behind Cologna.

Sundby beat Maxim Vylegzhanin in a tight sprint for the bronze, finishing 0.1 seconds ahead of the Russian. It was another near miss for Russia at the Laura Cross-Country Ski and Biathlon Center after Anton Shipulin finished fourth in the men’s biathlon sprint on Saturday, 0.7 seconds from a bronze.