Less than a week after being left out of Norway's team for the NH/10km, GRAABAK was inserted into the squad for the LH/10km and responded by winning gold. Magnus Hovdal MOAN (NOR) took silver and Fabian RIESSLE (GER) bronze.
GRAABAK came from sixth place after the ski jumping portion, 42 seconds behind half-time leader Eric FRENZEL (GER), to outlast everyone in a 10-athlete lead pack in the 10km cross country race and win by 0.6 seconds.
"My tactic was to ski well and hopefully to stay with the top guys," GRAABAK said. "It's a bit surreal. I will need time to enjoy the moment."
GRAABAK jumped 132m earlier on Tuesday to put himself among a group of seven athletes within 45 seconds of each other at the beginning of the cross country race.
Before the end of the first 2.5km lap, those seven had formed a group, with MOAN setting the early pace as the only one prepared to do the heavy lifting.
"I was skiing super fast in the two first laps, I had amazing skis," MOAN said. "I was hoping that the others would catch up (and take the lead) but it didn't happen."
German trio RIESSLE, Bjoern KIRCHEISEN and Johannes RYDZEK all started about a minute behind teammate FRENZEL but caught up by the 4km mark to create a pack of 10 athletes that skied together for the next 5km.
In the final kilometre, Norwegians GRAABAK and MOAN and Germans RIESSLE, KIRCHEISEN and RYDZEK left the others behind to create a five-man sprint finish for gold.
A collision on one of the tight corners in the finish area knocked RYDZEK out of contention, and the two Norwegians stormed ahead to win gold and silver for Norway's first 1-2 in Nordic combined at an Olympic Winter Games since 1936.
RIESSLE edged out teammate KIRCHEISEN by half a second for bronze, while RYDZEK ended up eighth.
"It all went black when I crossed the line," RIESSLE said. "I was lying there and couldn't believe what had happened."
FRENZEL (10th), Akito WATABE (JPN, sixth) and Jason LAMY CHAPPUIS (FRA, seventh) were among the pre-race favourites who skied in the lead group for almost all of the cross country race before fading at the end of the fourth and final lap.
This was Norway's first 1-2 finish in a Nordic combined event in 78 years. Oddbjorn HAGEN and Olaf HOFFSBAKKEN won gold and silver in the normal hill/10km event in 1936.
• Norway is the most successful NOC in this sport, having won 12 gold medals.
• This was Norway's first Olympic gold medal in Nordic combined since 1998, when it won the team event and Bjarte Engen VIK the individual event.
• MOAN won his third Olympic medal after claiming bronze in the normal hill/15km event and silver in the large hill/7.5km event in 2006.
• He became the fourth Norwegian to win at least three medals in this sport. He is one Olympic medal shy of the Norwegian record held by VIK and Fred Borre LUNDBERG.
Joergen GRABAAK (NOR) - gold
On winning gold:
"It's pretty obvious how I feel. I cannot really tell. It's a bit surreal. I will need time to enjoy the moment."
On his tactics:
"My tactic was to ski well and hopefully to stay with the top guys."
Magnus Hovdal MOAN (NOR) - silver
On his race:
"Honestly, on the last hill I didn't feel that I had the same legs as usual, and I'm quite lucky that the two Germans fell."
On whether he worked too much in the race:
"I don't remember having worked so much. I was skiing super-fast in the two first laps, I had amazing skis. I was hoping that the others would catch up (they would do the lead), but it didn't happen."
On winning the silver medal:
"I would like to say that it's the same as the world cup because I was competing with the guys I compete with every weekend, but it's only every four years (so it's different)."
"I'm happy to be back on the podium after 2006 (when he won silver and bronze in the individual events at the Torino Olympic Winter Games). This means that I still have something to do in this game."
Fabian RIESSLE (GER) - bronze
On winning bronze:
"It's absolutely awesome. It was an amazing race and I'm so happy. It's a big dream come true. It was so close. There were so many people on the last lap. It was amazing."
"It's a big fairytale for me. It was a great day for me even though it rained cats and dogs."
"I couldn't see anything. It all went black when I crossed the line. I was lying there and couldn't believe what had happened."
On how it feels to win the bronze medal:
"Absolutely amazing. It was very cool race today."
On whether he thought he would win this morning:
"No, surely not. I was very nervous last night and I did not get a very good sleep."