Story of the match
In the 10th minute, Rovers captain Darragh Lenihan was adjudged to have fouled Tarique Fosu in the area. Toney stepped up and coolly converted his 26th goal of the season.
Both sides struggled to keep possession from then on. The visitors enjoyed more of the ball but the pitch caused difficulties for the usually free-flowing West London club.
In the 32nd minute, Mathias Jensen was inches away from extending the lead, striking narrowly wide with an excellent strike after reacting first to a loose ball.
Eight minutes later, Vitaly Janelt had a rare but glorious chance to double the lead, latching onto Toney's knock-down but firing narrowly wide of Thomas Kaminski's post.
Toney nearly doubled his tally and Brentford's advantage in extraordinary fashion on the hour-mark, but his audacious effort from the half-way line was an inch too high.
Rothwell and Elliott combined brilliantly again in the 72nd minute, but the former was unable to get a clean strike on goal.
In the 80th minute, Toney had another chance to seal the three points in Lancashire, but the division's top scorer dragged his shot wide of Kaminski's post.
Kaminski made an outstanding save in the 87th minute to deny Sergi Canos from inside of the area, getting a glove to the Spaniard's headed effort from inside the six-yard box.
In stoppage time, Bradley Dack nearly dispossessed David Raya inside his area, but the Spanish goalkeeper was able to retain possession. However, the Rovers man injured himself in the process, leaving the pitch on a stretcher.
Swansea struggled to deal with Blackburn's frontmen on Tuesday, but Thomas Frank's men did a brilliant job to eliminate the threat they posed throughout the 90 minutes. They had several opportunities to seal the victory but ultimately held on to the all-important three points.
After four defeats in six games for Brentford, the three points at Ewood Park means that they move back to second place. Swansea and Watford will both have the opportunity to go above Brentford, should they win both win tomorrow.
The hosts showed quality going forward in stages, with 19-year-old Tyrhys Dolan often involved. He worked tirelessly in a relatively unfamiliar central striker role, with his attacking talents also on show.
For the visitors, Ivan Toney put in another brilliant performance. He won the majority of aerial duels and created a number of opportunities with his power and range of passing. He also scored the all-important winner, in a game that could prove vital at the end of the season.