Sanji proved that he still weak at the lastest episode of OP.
Did anyone actually expect Sanji to stand a chance in hell though? If Sanji was able to fight on par with or defeat Doflamingo, it would have been pretty bullshit, and taken most of all the suspense out of the rest of the arc for Luffy and Law's showdown with him. I had a conversation with Paty about all this people can read here, and in my opinion the Straw Hats are still massive underdogs. A lot of people seem to feel that Luffy and Zoro, right now at this point in time, are already capable of defeating the Admirals in 1 on 1 fights, and honestly if they are it would make me so disappointed and take so much of the suspense out of the story. One of the best parts about the story is that the Straw Hats have always had the risk of actually losing their battles. That's what gives them suspense. I'm going to quote myself from that post I linked to above:
Luffy lost to Crocodile twice before he beat him once, and was still almost killed by his poison (and would have been if it weren’t for Robin), he lost to Aokiji, he lost (they all lost) to Kuma, he lost to Magellan, and he lost a whole lot at Marineford. One Piece is not a manga where the protagonists always win, and I wouldn’t want the time skip to have changed this.
I'm not only expecting the Straw Hats to lose again as they travel through the New World, I'm hoping they do. Kuma's showdown with Zoro on Thriller Bark, and Kuma dispersing the Straw Hats on Sabaody were two of the most nail-biting and emotional scenes in the entire story, and they're times the Straw Hats were crushed. The idea that the Straw Hats are going to go through the New World and beat every single one of the Admrials and Yonkou in 1 on 1 fights without ever losing again is one of the most boring things I can imagine happening in this story. Oda has stated in his recent interview in Taiwan that he expects One Piece to continue for around 10 more years. Oda puts out an average of 44.4 chapters a year, so that means we can expect around 440 more chapters of One piece. That is plenty of time for the Straw Hats to have fights they lose and still move forward, and get much much stronger as they go.
Do you think there's a chance Law and Luffy will fight Doflamingo together? I mean Doflamingo is a powerful guy and both of them have a valid reason to fight him (Law for what happened 13 years ago, Luffy because he's the main character). Also, they're both captains in an alliance and it'd be cool to see them having each other's backs in a fight. Law already tried to fight Doffy alone and that didn't go well, but still his main reason for being there is still to kill the pink fluffy bastard.
I've been expecting them to fight Doflamingo together for a long time now. I've been expecting it both because they both want to defeat him themselves, and because I'm not confident either of them could do it alone. Law is stronger than Sanji, and Law got his ass kicked by Doflamingo every bit has hard as Sanji did, only landing a single cut on Doflamingo's cheek their whole fight before getting pelted into the ground outside the Colosseum and shot 3 times in the chest. And Luffy too, came out swinging in 2nd Gear against Doflamingo, and Doflamingo blocked it with no problem, slashed Luffy in the back, punched him in the face, and tossed him out into the street without breaking a sweat. Luffy's had even worse first showings against villains and still won in the end, but Doflamingo is more powerful and more built up than any villain Luffy has ever had to defeat before. Neither Law nor Luffy is backing down from this fight. Could you imagine either one of them standing on the sidelines while the other fights Doflamingo? Hell no. Unless Trebol comes along and forces one of them to fight him instead, there's no way either of them are going to miss out on fighting Dofla.
I'm also hoping that this arc sets a precedent that the Straw Hats will be willing to fight together against major enemies, like the Yonkou and Admirals. I'd very much like to see Luffy fight side by side with Jinbe or Kid or the other Supernovas against the likes of Big Mom and Kaidou.