As a result of his efforts, he jumped to third in the championship table and was the fifth man to win a SWC race this year.
The race action was stunning and the big news was the further improved pace of the BMW S1000RR. Aussie Troy Corser holeshot both races and was involved in racing that would have reminded him of his Australian 250 Production Championship days, except that 1000cc Superbikes are considerably faster than an RGV250 Suzuki.
In the end, Corser scored a pair of fifth place finishes, which does not do justice to his efforts on the transverse in-line four cylinder German bike. The racing was so close that in the first 22 lap affair, Corser was just 2.7 seconds off race winner Rea at the end and in race two, 4.1 seconds separated the first five.
James Toseland proved last year's championship winning Yamaha YZF-R1 is getting back to competitive form with 2-3 placings - impressive when he was coming from tenth on the grid each time.
With the factory Ducati team qualifying poorly and not figuring in either race, it was privateers Jakub Smrz and Carlos Checa who flew the Ducati flag, Smrz in the thick of the race one action until midway through when he was jumped by Leon Camier (Aprilia), Checa and Max Biaggi (Aprilia).
Race two was a nail-biter.
The first lap saw Haga run wide in the first turn, then Lorenzo Lanzi (Ducati) tagged the rear wheel of Tom Sykes' Kawasaki sending them both down and out. Both walked away.
Again Corser blasted the BMW into the lead off the start but this time Rea sliced past early while Leon Haslam (Suzuki) sat in fourth. He had been slowed in the first 22-lap bash by a slowly deflating front tyre but was back at his storming best for the second race, passing the Aprilia of Leon Camier early on then taking Corser just as Rea made another bid for the lead.
Corser hit back to regain second spot on lap six then retake the lead from Rea. The order then was Corser-Rea-Haslam-Camier-Toseland-Biaggi-Checa-Smrz - the eight of them nose-tail.
Mid-race, Haslam made his move, outbraking Corser then Rea on successive laps to head the freight train for three laps before Rea came by. The pair of them swapped the lead three times in a lap, Rea finally getting a gap and edging away to his second win of the weekend while Haslam left Corser in the clutches of Toseland, Camier and Biaggi.
Corser could not quite get to the fourth place he scored in Valencia at the previous round but this weekend's two fifth places were even more impressive rides, particularly when added to the fact that he topped combined qualifying, and was third fastest in Superpole on Saturday.
At the end, Toseland had enough left to secure third, his second podium of the weekend while Camier crashed spectacularly with three laps to go, handing team-mate Biaggi an extra two points in the championship in the process.
At the end of both races, the podium was made up entirely of British riders, an unusual situation but one we may see more of as this championship develops.
Talking about the Championship, Haslam continues to lead on the Suzuki GSX-R1000, Biaggi maintains the runner-up spot he took after his double win at Portimao and Rea's Assen double moves him up to third, ahead of Carlos Checa. Others to make up ground are Toseland (from sixth to fifth) while Corser moved from ninth to seventh.
With 18 races to go, the title chase is wide open, although Haslam will be keen to retain his lead after the May 9 round at Monza. Last year Fabrizio won the first race there after Ben Spies' Yamaha ran out of fuel, and then the Italian Ducati rider finished second in race two after Yamaha made no mistakes with the fuel.
Ducati will be desperate for some good results from the works team on May 9 but with Haga sixth in the title chase, 63 points off Haslam's lead, he has a big job to do.
Assen was a troubled time for the official Xerox Ducati team. Haga was only 10th in the frst race and retired in the second with a bad engine vibration and while Fabrizio scored in each race, 13th and 12th was not what the team was looking for.
Is it a coincidence that since Davide Tardozzi left the works Ducati squad to manage BMW's effort, the relative fortunes of the two teams have changed?
One thing is certain: BMW is not leaving any stone unturned in its efforts to get the four cylinder S1000RR onto the podium. The new electronics have been a big help, but Corser said that towards the end of the first race it was spinning up the rerar tyre again. With its speed, and some more elctronic work, perhaps Monza will be a happy hunting ground...
2010 WSB The Netherlands - Assen 25/04/2010
Race 1 - 22 Laps
Pos. Rider Manu. Nat. Total Time
1 Jonathan Rea Honda GBR 35'38.483
2 James Toseland Yamaha GBR 0'01.106
3 Leon Camier Aprilia GBR 0'01.249
4 Carlos Checa Ducati ESP 0'01.548
5 Troy Corser BMW AUS 0'02.738
6 Max Biaggi Aprilia ITA 0'02.813
7 Jakub Smrz Ducati CZE 0'06.296
8 Cal Crutchlow Yamaha GBR 0'12.022
9 Shane Byrne Ducati GBR 0'12.146
10 Noriyuki Haga Ducati JPN 0'19.753
11 Leon Haslam Suzuki GBR 0'22.204
12 Tom Sykes Kawasaki GBR 0'22.282
13 Michel Fabrizio Ducati ITA 0'22.780
14 Sylvain Guintoli Suzuki FRA 0'23.364
15 Luca Scassa Ducati ITA 0'37.097
Fastest Lap: Carlos Checa 1m 36.413s - 169.600 km/h
Race 2 - 22 Laps
Pos. Rider Manu. Nat. Total Time
1 Jonathan Rea Honda GBR 35'43.137
2 Leon Haslam Suzuki GBR 0'01.942
3 James Toseland Yamaha GBR 0'03.928
4 Max Biaggi Aprilia ITA 0'04.067
5 Troy Corser BMW AUS 0'04.176
6 Carlos Checa Ducati ESP 0'04.525
7 Jakub Smrz Ducati CZE 0'04.682
8 Shane Byrne Ducati GBR 0'07.698
9 Max Neukirchner Honda GER 0'09.903
10 Ruben Xaus BMW ESP 0'11.465
11 Luca Scassa Ducati ITA 0'15.489
12 Michel Fabrizio Ducati ITA 0'23.604
13 Sylvain Guintoli Suzuki FRA 0'29.085
14 Chris Vermeulen Kawasaki AUS 0'35.401
15 Matteo Baiocco Kawasaki ITA 0'44.330
Fastest lap: Rea, 1m 36.312s - 169.773 km/h
Rider Championship Standings
1. Leon Haslam Suzuki GBR 148
2. Max Biaggi Aprilia ITA 128
3. Jonathan Rea Honda GBR 110
4. Carlos Checa Ducati ESP 103
5. James Toseland Yamaha GBR 86
6. Noriyuki Haga Ducati JPN 85
7. Troy Corser BMW AUS 68
8. Sylvain Guintoli Suzuki FRA 55
9. Michel Fabrizio Ducati ITA 53
10. Cal Crutchlow Yamaha GBR 49
11. Leon Camier Aprilia GBR 48
12. Shane Byrne Ducati GBR 48
13. Jakub Smrz Ducati CZE 38
14. Lorenzo Lanzi Ducati ITA 26
15. Ruben Xaus BMW ESP 25
Manufacturer Points
1. Suzuki 148
2. Aprilia 134
3. Ducati 130
4. Honda 111
5. Yamaha 93
6. BMW 69
7. Kawasaki 19