The UFC has added a second title fight to its April 25 pay-per-view card in Montreal.
Demetrious (Mighty Mouse) Johnson will defend his flyweight championship belt against Japan's Kyoji Horiguchi, ranked eighth among 125-pound contenders, in the co-main event of UFC 186.
Bantamweight title-holder T.J. Dillashaw meets Brazil's Renan Barao in the main event at the Bell Centre.
The Johnson-Horiguchi bout replaces the original co-main event featuring welterweight contenders Rory MacDonald and Hector Lombard.
The UFC offered no reason for pulling the MacDonald-Lombard fight, saying only other bouts were being considered for the two and another matchup would be announced at a later date.
MacDonald, ranked No. 2 among 170-pound contenders, had hoped to fight for the title next. UFC president Dana White said as much before then-champion Johny Hendricks faced (Ruthless) Robbie Lawler at UFC 181 in December. Hendricks had beaten Lawler at UFC 171 last March to claim the title vacated by Montreal's Georges St-Pierre.
Instead of having MacDonald face the winner, the UFC opted to stage a third Hendricks-Lawler bout.
With Lawler opting not to fight until the summer, Hendricks has been matched again Matt (The Immortal) Brown at UFC 185 on March 14 in Dallas.
The removal of MacDonald (18-2) from the Montreal card raises questions about whether the welterweight apple-cart has been further upset.
The 25-year-old MacDonald, a native of Kelowna, B.C., who fights out of Montreal, has won eight of his last nine bouts. Lombard (35-4-1 with one no contest) is ranked fifth among welterweight contenders.
Johnson (21-2-1) has defended his flyweight title five times since winning a split decision over Joseph Benavidez at UFC 152 in September 2012 to become the first 125-pound champion.
Horiguchi (15-1) has won all four of his UFC fights.
