Sometime back we wrote a blog on "How Vishnu Helped Shiv". In fact Vishnu has always been helpful to other Devtaa, whether it is Shiv or Brahmaa or other Devtaa. Today we will tell you a story when Shiv fought with Vishnu. It seems strange in hearing, but it it is true. For this we have to go long back in history - in Krishn's times.
Story of Ushaa and Aniruddh
There was an Asur named Baanaasur in the family line of Hiranyakashyap; Hiranyakashyap --> Prahlaad --> Virochan --> Bali --> Baanaasur. When Narasinh Bhagvaan killed Hiranyakashyap, He granted a boon to Prahlaad that He would not kill anybody in his lineage.
Now Baanaasur had a daughter named Ushaa. He loved her very much so he cared for her very much. As the time went on, Ushaa grew up in a fine young woman. One day she went to Devee temple and asked her as who will be her husband. Devee said - "On one night you will see a Prince in your dream, the same Prince will be your husband." So according to Devee's statement, one night Ushaa saw a Prince in her dream. She got attracted to him and as he made love to her (of course in her dream), she woke up and got very sad at her separation from that prince. She started crying for him. Her dream was gone but she could not forget that Prince. She became sad and sickly remembering him.
Ushaa had a friend, Baanaasur's Minister's daughter, Chitralekhaa. Chitralekhaa noticed this and asked her the reason for her sadness. Ushaa told her everything. She asked her who was he, but Ushaa could ot tell anything about him. Chitralekhaa was a good artist so she drew many sketches and at last got success in making out the name of that Prince. That Prince was Aniruddh, son of Pradyumn (Krishn's son). She knew some Maayaa too, so one night she brought sleeping Aniruddh to Ushaa to please her and put him in bed near Ushaa.
Now Ushaa was very happy to see the Prince of her dream. Aniruddh stayed there for some time. Ushaa's palace was separate and well-secured and well-guarded. After a while Ushaa got pregnant and the marks of her pregnancy appeared on her body. One day the guards noticed this and reported to Baanaasur. Baanaasur doubted their security measures but the guards assured him that nobody else came in the palace of the Princess in their knowledge. Baaanaasur himself came there found Aniruddh living there. he got very angry at this.
Shiv Fights With Krishn
On the other side Krishn and Pradyumn were worried at Aniruddh's disappearance. came to know from Naarad Jee that Aniruddh was living in Baanaasur's palace, so they both came with their army either to marry Aniruddh to Ushaa or to fight with Baanaasur. Baanaasur had a boon from Shiv Jee that he would guard his city, so when Krishn and Pradyumn came to Baanaasur with their army, Shiv's Gan came to fight with Krishn. Krishn's army was defeating. Shiv's Bhoot Gan so they started running away. Shiv Jee released a 3-headed and 3-feet Jwar burning all directions Seeing this Jwar coming Krishn released His own Jwar and both Vaishnav Jwar and Maaheshwar Jwar started to fight. At last Maaheshwar Jwar got defeated and came in the shelter of Krishn. Krishn made him fearless and that Jwar went away.
In the meantime Baanaasur came to fight, but Krishn spared him just cutting his all arms (he had 1,000 arms) leaving his 4 arms. Shiv came to Krishn and requested His grace for his devotee. Krishn replied - "Hey Mahesh, Otherwise also I could not have killed him as I have already promised to Prahlaad that I will not kill anybody in your lineage."
Then Baanaasur came to Krishn with Ushaa and Aniruddh. He married them and on Shankar's request Krishn appointed Baanaasur as Shiv's Chief Paarshad.
That is how Shiv fought with Vishnu to protect his devotee Baanaasur. Read this story in full here in Bhaagvat Puraan, 10/u10