Alaphilippe has been the outstanding rider this season with eight victories, including Milan-San Remo, but Van der Poel, the 24-year-old cyclo-cross world champion, has stormed onto the road in his first spring classics campaign, with victory at Dwars door Vlaanderen and fourth place at the Tour of Flanders and Gent-Wevelgem.
The pair went head-to-head at Brabantse Pijl on Wednesday, where Van der Poel left the more experienced Alaphilippe to win the sprint from the select four-man group. They will lock horns again at Amstel Gold Race on Sunday.
"I was happy for him," Alaphilippe said ahead of the Dutch Classic. "I do not know him personally, we have not ridden against one another much, but I have followed him a bit because I like cyclo-cross. It's a pleasure to see him doing well in 'cross and now doing it as well on the road. What he's doing is a good thing for cycling."
Ahead of the spring, Van der Poel's director at the Corendon-Circus team said the Classics would be a 'playground' for Van der Poel, and indeed he has not been shy to attack and open the race from distance, despite his inexperience. At Brabantse Pijl he but in a couple of big attacks way out, and still had the strength to make the final selection and then win the sprint from it.
"I love his way of racing. He is a phenomenon. More than a 'crosser, he's someone who can do everything well. I'm happy he's now also on the road," Alaphilippe said.
"For Amstel he is one of the top favorites. Certainly, he rides his own race, is doing very well and has gained confidence over the past few weeks."
Alaphilippe himself took heart from his second place on Wednesday, pointing out that second places are now viewed as sub-standard for him after his sparkling run of form in the past 12 months. Nevertheless, he played down his chances at Amstel - and indeed at next week's Flèche Wallonne and Liège-Bastogne-Liège - saying he's not in the shape he was this time last year.
That's partly because he tried to hit top form earlier in the Classics, for Strade Bianche and San Remo, but also because he was forced to abandon the Tour of the Basque Country, a key preparation race for Ardennes contenders, after a crash on stage 3.
"I needed quite a bit of time to recover. I had pain everywhere and I had trouble breathing. That was annoying. I'm no longer in pain, but it was certainly not ideal preparation," Alaphilippe said.
"I'm ok now, it could have been worse, and in Brabantse Pijl things went well again, but I don't have the same condition as last year. I had really made a goal of a first peak for Strade Bianche, Tirreno-Adriatico, and Milan-San Remo. Then I took my foot off and the counter went back towards zero. The condition is now on the up, it's getting better and better, but it's not like last year.
"Of course, I want to do well in the hilly Classics, they're races I love, but I'm relaxed. I start with less pressure because I have all those victories in my pocket."