On 8 February 1940, the 5./7 IAP (15 pilot led by Kapitan A. Ye. Mol’bin) arrived from 18 IAP of Far East Army Corps (DVK) after a departure on 26 January to take part in the Finnish-Soviet Winter War. Later also personnel of 70 IAP and 22 IAP (which both had fought in the Khalkhin Gol-incident in August 1939) arrived.
Kapitan Mol’bin was shot down by AA-fire at Tikkola and killed on 14 February, when escorting SB-bombers. Starshii Leitenant Iosef Geibo took over 5./7 IAP, which received I-153s from 17 February.

7 March was another day of heavy claiming from 7 IAP when they claimed seven bombers and one fighter.
Leitenant Aleksandr Moshin (credited to him as a single destroyed by Bykov), Sayenko and Malyshev of 2./7 IAP (I-16) claimed a shared Blenheim over Koivisto peninsula.
Viktor Skryabin of 2./7 IAP (I-16) claimed a Blenheim over Vilaniemi.
Kuzmenko of 5./7 IAP (I-153) claimed a fighter.
Golubev and Foma Tikhomirov of 5./7 IAP (I-153) claimed a shared Blenheim.
Il’ya Kaynov and Balashov of 5./7 IAP (I-153) claimed a shared Blenheim.
Kaynov later claimed a second shared Blenheim with Aleksey Rybalov (from the same unit).
Major Aleksandr Ketov (credited to him as a single destroyed by Bykov), Vladimir Semenishin and Vavilov of 1./7 IAP (I-16) claimed a shared Blenheim.
Starshii Leitenant Fedor Shinkarenko of 4./7 IAP (I-16) claimed a Blenheim.
To add to the confusion did Starshii Leitenant Dyachenko of 25 IAP (I-153) claim a shared Blenheim at kv. 093 (28. AK sector) together with 7 IAP but it’s unclear with whom.
Two Finnish Blenheims were in fact lost in the Viborg area when LeR 4 attacked targets on the ice of the Gulf of Vyborg and on the shore on 24 sorties during the day.
Blenheim BL-144 of LLv 42 was lost at 07:30. The pilot kersantti Toivo Hyytiäinen and gunner kersantti Eelis Turunen were killed while the observer vänrikki Kauko Nykänen parachuted to become a PoW.
Blenheim BL-122 of LLv 46 was lost at 12:15. The pilot luutnantti Niilo Hakla parachuted wounded while the observer luutnantti Pekka Salokoski and gunner kersantti Arvi Pakkala both were KIA.

Balashov ended the war with 1 shared biplane victory.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1940
	07/03/40		1/2	Blenheim (a)	Shared destroyed	I-153		Gulf of Vyborg	5./7 IAP

Biplane victories: 1 shared destroyed.
TOTAL: 1 shared destroyed.
(a) 7 and 25 IAP totally claimed 7 bombers and 1 fighter without losses. 2 Blenheims from LeR 4 were lost.

Sources:
All aces of Stalin 1936–1953 – Mikhail Bykov, 2014
Red Stars 7 - Talvisota Ilmassa - The Winter War In the Air - Carl-Fredrik Geust, 2011 Apali Oy, Tampere, ISBN 978-952-5877-04-5
Soviet airmen in the Spanish civil war 1936-1939 - Paul Whelan, 2014 Schiffer Publishing Ltd, ISBN 978-0-7643-0
Suomen Ilmavoimat part II – 1928-40 – Kalevi Keskinen and Kari Stenman, 2006, ISBN 952-99743-0-2